C2-028.840.01.09.02.pdf

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© Siemens, 2006- For internal use only - All documents may onlybe used by authorized personnel for renderingservices on Siemens Healthcare Products. Anydocument in electronic form may be printedonce. Copy and distribution of electronic docu-ments and hardcopies is prohibited. Offenders

will be liable for damages. All other rights are re-served.

Print No.:

SiemensGrimm

SOMATOM Definition

Gantry

Troubleshooting Guide

CT

2006

C2-028.840.01.09.02

Replaces: C2-028.840.01.08.02

EnglishDoc. Gen. Date: 08.11

n.a.H CXCS SD CR-CT

Instructions for Troubleshooting

© Siemens,2006

07740777

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2 Copyright / Version / Disclaimer

SOMATOM Definition C2-028.840.01.09.02 © Siemens, 200608.11 H CX CS SD CR-CT

Page 2 of 176For internal use only

1Copyright/ Version/ Disclaimer

Copyright

“© Siemens, 2006“ refers to the copyright of a Siemens entity such as Siemens Aktienge-sellschaft - Germany, Siemens Shenzhen Magnetic Resonance Ltd. - China, SiemensShanghai Medical Equipment Ltd. - China, Siemens Medical Solutions USA Inc. - USA

and/or Siemens Healthcare Diagnostics Inc. - USA.

Document Version

Siemens reserves the right to change its products and services at any time.

In addition, manuals are subject to change without notice. The hardcopy documents corre-spond to the version at the time of system delivery and/or printout. Versions to hardcopydocumentation are not automatically distributed. Please contact your local Siemens officeto order current version or refer to our website http://www.healthcare.siemens.com.

DisclaimerSiemens provides this documentation “as is“ without the assumption of any liability underany theory of law.

The service of equipment described herein is to be performed by qualified personnel whoare employed by Siemens or one of its affiliates or who are otherwise authorized by Sie-mens or one of its affiliates to provide such services.

Assemblers and other persons who are not employed by or otherwise directly affiliated withor authorized by Siemens or one of its affiliates are not entitled to use this documentationwithout prior written authority.

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© Siemens, 2006 C2-028.840.01.09.02 SOMATOM Definition08.11 H CX CS SD CR-CT

Table of Contents 3


0TableofContents

1 _______ General ________________________________________________________ 7

Safety information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Safety warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Information for switching off the gantry power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Service Push-Button S1 in PDC-A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Safety bolts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Data ring protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2 _______ XRS __________________________________________________________ 15

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Definitions and abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Prerequisites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Problem isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Generator oscillator procedure (GenOSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Flowchart for HV Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

XDC/Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20XDC/Tube Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20XDC/Tube test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

High voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21TSG high voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Check/adjust the tube oil pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23HV plugs with arcing tracks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26HV plug installation at HV sockets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28High voltage tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Filament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32TSG filament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Filament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Anode rotation (RAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33TSG Anode Rotation (RAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Single pulse test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Single pulse test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Single pulse test diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Arcing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

XRS hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Switching on status display of XGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Measuring points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Measuring points D700, D701, D702, D703 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43LED´s on D700, D701, D702, D703 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

3 _______ DMS__________________________________________________________ 56

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

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4 Table of Contents



Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Definitions and abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

TSG Image Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58TSG strong rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59TSG sporadic strong rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60TSG weak rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62TSG sporadic weak rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63TSG rings in outer slices only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63TSG Streak artifacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64TSG Dual Source problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65TSG Spatial Resolution (bad MTF results) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67TSG other artifacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68Tests for Image Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

TSG DMS Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88TSG DMS Power path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88TSG UHR mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Additional Tests & Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96Storage of Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96Hints for defective channel detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97Separate between module and other components . . . . . . . . . . . . . . . . . . . . . . . . . . 98How to interpret the physicist’s line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

4 _______ Datalink______________________________________________________ 100

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Definitions and abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100General: Receivers with Revision <B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

TSG Datalink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103TSG permanent errors on DAS Controller/s -> IRS Receiver/s. . . . . . . . . . . . . . . . 103TSG data quality at Tx module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105TSG data quality at RX modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

TSG sporadic errors in link DCON -> IRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107Step 1 (checking). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108Step 2 (debugging) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108Step 3 (localizing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Tests for data transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114Cleaning a fiber optic cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114Data Link Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118How to check the transmitting antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118Measuring the fiber optic signal along the link. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119Check the electrical RF signals at the Rx modules . . . . . . . . . . . . . . . . . . . . . . . . . 119

Check the quality of data signal (jitter) at the G-REC input . . . . . . . . . . . . . . . . . . . 120

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8 _______ Cooling System _______________________________________________ 160

Cooling System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Water Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Air Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

9 _______ Changes to Previous Version ____________________________________ 174

10 ______ Index ________________________________________________________ 175

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General 7


1- 1General

Safety information 0

Only qualified and system-trained service staff is allowed to perform CT system installation,service , maintenance and quality assurance. Ensure that the most recent version of theservice documentation is available.

To avoid any risk of injury to persons and/or damage to the system read and observe theGeneral Safety Notes (TD00-000.860.01.xx.xx). Please read and observe the Product-specific safety notes (C2-028.860.01.xx.xx) which include very important safety-relatedinformation as well as information about handling of screws and nuts, use of Loctite andinstructions for torque wrenches. You will find the following information in the “Product-spe-cific safety notes.”

• Safety information related to the method of risk management (C2-028.860.01 / Generalsafety warnings).

• General safety information such as the handling of service documentation, CT systemtraining request, X-ray protection, electrical protection, service tools....(C2-028.860.01 /

General safety information).• General safety information about working in the gantry with the power off/on

(C2-028.860.01 / Working in the gantry with gantry power off).

• Use of the patient table as lifting device for gantry part replacement (C2-028.860.01 /Usage of patient table as lifting device).

• Laser products (C2-028.860.01 / Laser Products).

• Attachment of screws and nuts, use of Loctite, adjustment instructions for the torquewrench (C2-028.860.01 / Screw Connections).

Safety warnings 0

The following safety information is an extract of the information in the Product-specificsafety notes (C2-028.860.01.xx.xx) (C2-028.841.01 / Safety information). It is mandatoryto read and observe the safety information described below.

CAUTION [ hz_serdoc_F13G02U01M04 ]

Flammable sprays.

Risk of inflammation!

Only use approved and recommended cleaning agentsas described.


Handling parts of the system that may have come into con-tact with patients may lead to infection caused byblood-borne pathogens.

Infection caused by blood-borne pathogens!

Take appropriate precautions against exposure toblood-borne pathogens (e.g. wear gloves).

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8 General



WARNING [ hz_serdoc_F13G01U13M02 ]

High voltages and/or mechanical movements (e.g. gantryrotation) may lead to accidents and injuries when openingsystem covers.

Risk of accident and injury!

Only authorized service personnel is allowed to opensystem covers.


Not following X-rays protective regulations may lead to radi-ation exposure to you and/or other persons.

Risk of radiation exposure!

Observe radiation protection regulations when X-rays areswitched on, e.g. :

Never work inside the gantry room.

Do not leave the system unattended.

Make sure there isn't anyone inside the gantry room.

Make sure that no person can enter the gantry roomunnoticed (e.g. lock doors if necessary) .


Dangerous voltages are present when the system is switchedon. Dangerous voltages may be present even when the sys-tem is switched off due to capacity power.

Risk of electric shock!

Observe power-off instructions and discharge waittimes (allow at least five minutes discharge time afterthe last scan for all involved HV and UDC/UPS parts).

Secure the system against unintended switch-on (e.g.block breaker and/or mark breaker against switch on).

Ensure via measurements that all voltages areswitched off.

Connect the stationary and rotating parts of the gantryto a protective conductor prior to working in the gantry.


Rotating parts are exposed when gantry covers are opened.

Risk of injury!

Maintain a safe distance and ensure that objects do not

come in contact with rotating parts.

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General 9



Unfixed parts/cables during gantry rotation.


Make sure that all parts and cables are mounted prop-erly before starting rotation.


Temperature of tube and/or tube cooling device parts maybe above 70C (with Straton up to 130C).

Risk of burns!

Avoid contact with oil and exposed parts of X-ray tubeand cooling device.

Wait until tube and cooling device parts are chilleddown.

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10 General



Information for switching off the gantry power 1.1

• Switch off system (Click <SYSTEM> and select <END> in the user main menu to switchoff the system automatically after shut down). Additionally, switch off the gantry powerusing service pushbutton S1 in PDC-A (C2-028.841.01 / Service Push-Button S1 in

PDC-A). Secure against unintended switch-on.

NOTE Read and observe the safety information in the “Product-spe-cific safety notes” prior to performing service work in thegantry. If the gantry power is switched off for service work,always secure it against accidental switch on.

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General 11


Service Push-Button S1 in PDC-A 1.2

Fig. 1: Service push-button S1Pos. 1 Service push-button S1

Pos. 2 Push-button

If S1 is pressed the complete power supply for the gantry is switched off. As well as thepower input to the DC-Link of XGS_A and XGS_B. The circuit breakers F2, F3, F5, F6, F7,F11 in PDC_A and F2 in PDC_B get tripped through an additional shunt trip attached tothe circuit breakers. For normal operation the circuit breakers have to be reset manually.

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12 General



Safety bolts 1.3

• Front safety bolt -> located at bottom right gantry front

• Back safety bolt

Fig. 2: Rotation safety lock - unlock position

Fig. 3: Rotation safety lock - lock position

• Unlock position of gantry front safety bolt (item 1)

• Lock position of gantry safety bolt (item 2).

Fig. 4: Rotation safety lock - back

• Back rotation safety bolt (item 1) located between XGS A and HV-tank A at theback of the gantry.

• Lift bolt and turn it 90 degrees to bring it into the lock or unlock position.

Make sure that the bolt is really at the correct (lock/unlock) posi-tion. If the bolt accidentlally moves into the lock position duringrotation, the gantry may be damaged.

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14 General



Data ring protection 1.4

• Installing data ring protection

Fig. 7: Data ring protection

• Install the 2 data ring protectors (e.g. item 1) before working at the gantryfront.

- 2 Plexiglas protectors are necessary to cover a larger area on the data ring.

- Attach them to the stationary data ring.

- Do not forget to remove the protectors before starting gantry rotation.

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XRS 15


2- 2XRS

General 0

Safety 0


Avoid accident and injury or damage to parts.


Read and observe the safety information contained inthe “General” section of this document and/or the“Product specific safety notes”.

Notes 0

This section contains information on isolating XRS problems

• Section “General” -> General information..

• Section “Overview” -> XRS Information.

•

• Section “High voltage” -> High voltage TSG followed by high voltage test descrip-tions.

• Section ”Filament” -> Filament TSG followed by filament test description..

• Section ”Anode rotation” -> Anode rotation TSG followed by RAC test description..

• Section ”XRS hints” -> XRS hints.

• Section ”Measuring point” -> Table of LEDs and measuring points on XGS/XRS.

Definitions and abbreviations 0

Tab. 1 Definitions and abbreviations

Term Definition / Abbreviation

XDC X-ray deflection control

XGR X-ray generator, rotating

XGS X-ray generator, stationary

XRS X-ray system

XRT X-ray tube

XTA X-ray tube assembly

XTC X-ray tube cooling

MVT Middle voltage transmission

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16 XRS



Prerequisites 0

Documents

n.a

Tools and auxiliary equipment

• Standard tool kit

• HV test plugs

HVT High voltage tank

TSG Troubleshooting guide


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XRS 17


Overview 2.1

The XRS section contains information on possible XRS tests and the corresponding trou-bleshooting guides. In the SOMATOM Definition, troubleshooting always starts by callingup the EventLog and searching for the relevant error message. Follow the instructions

given in this error message for troubleshooting. In some cases, the error message will linkyou to troubleshooting instructions as described in this document. This link is normallyused if the troubleshooting instructions are too complex or images are needed for trouble-shooting.

Additionally, read the information which is stored in the tube history (Local Service->Report). This information can always be useful in case of XRS problems.

Problem isolation 0

Principle problem isolation in case of XRS problems

1. Find relevant error message in Eventlog

NOTE The XGR and XGS assemblies are continuously communicat-ing using the CAN bus after the system is switched on. Forthis reason, 2 error messages are usually sent to the log-book after XRS problems. Always check both (XGS/XGR)error messages when troubleshooting.

2. Follow the instructions given in the error message text for troubleshooting

The information provided in the error message will guide you in finding the prob-

lem. In some cases, you will be linked to this Test and Troubleshooting instruc-tions, # C2-028.840.01.... In this case, follow the relevant troubleshootinginstructions described in this document.

Generator oscillator procedure (GenOSC) 0

Generator oscillator adaptation (Gen-Osc) is an automatic program. The purpose of theprogram is to adapt the inverter frequencies. The program performs very short scans withdifferent inverter frequencies to find the minimum resonance point. This value is stored toD700 in XGS.

The frequency adaptation procedure must run successfully; otherwise, XRS errors suchas UT too high or UT max errors (e.g XRS_83 error) may abort scanning. The same errorsmay appear if parts of the oscillating circuit (MV cable, XGS_PDC_Control, HVT / MVT)have been replaced without performing GenOSC after exchange. For this reason, alwaysuse the relevant guided tour after part replacement.

NOTE If GenOsc fails because of arcing, try using dummy plugs (i.e.test plugs for HVT) and perform GenOsc again with dummyplugs installed.

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18 XRS



Flowchart for HV Troubleshooting 0

The flowchart (Fig. 8 / p. 19) gives a guideluine how to deal with tube arcings and repre-sents the algorithm behind the tool “SOMATOM Definition HV Troubleshooting”. For moreinformation regarding this tool, see the documentation for CT016/09/R.

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©

S i em en s ,2 0 0 6

C 2 - 0 2 8 . 8 4 0 . 0 1 . 0 9 . 0 2

S OMA T OM D ef i ni t i on

0 8 .1 1

H

C X C S S D

C R- C T

P a g e1 9 of 1 7 6

F or i n t er n al u s e onl y

Fig. 8: HV Troubleshooting Flowchart

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20 XRS



XDC/Tube 2.2

XDC/Tube Test 0

INIT Tests:

During INIT, all XRT drivers of the XDC (outputs on X13 and X14) are tested in 2 steps. Thefirst step is an isolation check for detecting short circuits between the output wires andground or power (230 V). This step can detect defective driver gates within the XDC as well.The second step activates the drivers and can detect short circuits between the outputwires or broken wires. The INIT tests have failed if any warning or error message occurs inthe Eventlog during step 1 or 2, or if the requested currents in step 2 cannot be reached.

XDC/Tube Self-Test within Service SW:

The XDC/Tube self-test is basically the same as the INIT test. Depending on the actual sys-tem state, the XDC/Tube self-test tolerates some problems. So, if the XDC/Tube self-test

fails, switch the gantry off/on to initialize an INIT test.Test results:

If the test fails, it results in error message " CT_DCA/B 31" where the parameters givesome information on which part of the test failed. In addition to this information, there canbe additional errors or warnings which indicate the error. Follow the instructions in thewarning/error message for troubleshooting

Usage of the tests:

The XDC/Tube self-test can help detect problems in the output drivers of the XDC, prob-lems within cabling, or problems within the tube. The test can be helpful if the XDC hasaborted scans with the error message "CT_DCA/B 51 ..." or "CT_DCA/B 50", especially

if parameter 3 is 0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x12, 0x17, 0x1D, 0x1E or 0x1F. Beaware that any of these errors can happen during arcing as well, without any real HW prob-lem within the XDC or the tube. If the INIT tests fail, you have a problem in the XDC, cabling,or the tube. If any additional error or warning message occurs in the Eventlog during INIT,it can be used to help detect where the problem is located. You can disconnect the cableon the XDC (X13 and X14) and/or the tube (X8 and X4) and then repeat the INIT test. Whenthe additional errors/warnings disappear, you have disconnected the faulty part from theXDC.

Remark: Test can be used if the system is in or is not in stand-by status.

XDC/Tube test 0

XDC/Tube test

Performing the filament test

1. Select Local Service > Test Tools > Tube/Generator

2. Select XDC/Tube.

3. Click GO and follow the instructions in the dialog. The test is terminated automatically.

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High voltage 2.3

TSG high voltage 0

The following high voltage TSG has to be used in case of high voltage problems. The TSGstarts at the XRT (X-ray tube) and provides guidance through the HV related components.

NOTE XRS components cannot be exchanged from system A tosystem B or vice versa for troubleshooting.

NOTE Always use new silicon insulators at the HV sockets ((HVplug installation at HV sockets / p. 28)) as well as new silicondisks at the HVT when installing the cable plugs or the test

plugs.

Tab. 2 High voltage TSG

Step Action

1 • Check Eventlog for UT max and /or UT too high errors (e.g XRS_83) or arc-ing problem (XRS_68).

• If there are UTmax and /or UT too high errors, perform GenOSC (Local Ser-vice -> Tune Up -> Expert Mode -> GenOSC).

a) if GenOSC is aborted due to a problem -> continue with item 2

b) if the HV problem is not solved after GenOSC -> continue with item 3.

c) if the HV problem is solved -> GenOSC tables are stored in D700 XGS.No further action necessary.

2 • If there is any doubt that the oil pressure is correct, check the oil pres-sure.Too low oil pressure especially in the “older”1.05bar- typ of Definitiontubes is very critical compared to 1.25bar- tybe of tubes.

• Perform GenOSC with installed test plugs. See (HVC plug test / p. 30) fortest plug installation.

a) if the GenOSC still aborts -> check the Eventlog for CT_GSA/GRA

messages and follow the instructions given in the error message.b) if the GenOSC is ok -> try GenOSC again with installed X-ray tube -> if

problem recurs, change XRT (X-ray tube).

3 • Perform Gettering (Local Service -> Tune Up -> Expert Mode -> Getter).

a) if the HV problem is not solved after gettering the tube -> continue withitem 4

b) if the HV problem is solved -> no further action.

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22 XRS



4 1. Switch off system (select System -> END) and press service switch S1 inPDC_A (Service Push-Button S1 in PDC-A / p. 11).

2. Switch off rotation enable switch S301.3. Remove HV plugs from the HV sockets (beside the tube).

4. Remove insulators from the HV plugs.

5. Check HV plugs and the 2 insulators for signs of arcing (black dots or stripes)(HV plugs with arcing tracks / p. 26).

a) If there are any signs of arcing -> continue with item 5

b) If there are no signs of arcing -> continue with item 6.

5 • If there are any signs of arcing on the plugs, HV sockets, or the insulators.

a) Clean HV plugs and the 2 sockets (inside) with alcohol.

b) If any signs of arcing (cracks) remain on the plug or HV sockets ->change the relevant part(s).

c) If there are no signs of arcing remaining on the parts -> reinstall HV plugsusing new silicon insulators (HV plug installation at HVsockets / p. 28).

d) Try scanning again -> if the HV problems reoccur continue with item 6.

6 • Perform HVC tube test. Follow the dialog of the HVC tube test (tube test withHV but without load).

a) If there are no XRS HV error messages found in the logbook ->continue

with item 11.b) If there are XRS HV error messages found in the logbook -> continue

with item 8.

7 • Perform HV plug test with installed dummy plugs ( #10 093 700) at HV sock-ets (HVC plug test / p. 30). Follow the dialog of the HVC plug test. (LocalService --> Test Tools --> Generator --> HVC plugs)

The HV test plugs have to be installed using new insulators and haveto tightened with a torque of 25 Nm . (HV plug installation at HVsockets / p. 28)

a) If the test is aborted after 80 s by the UMAR (scan time exceeded), there

is no HV problem on generator side --> change tube.

b) If there are still XRS HV error messages found in the logbook -> con-tinue with item 8.

Step Action

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XRS 23


Check/adjust the tube oil pressure 0

An incorrect oil pressure can result in various errors.

If the oil pressure is too high, the tube would activate the oil pressure safety switch or theoil temperature safety switch, when the tube gets hot.

The more likely case, though, is that the oil pressure is too low.

Especially in the Somatom Definition (dual source), the earlier type of tubes needs to beadjusted to 1.05 bar, current tubes need a pressure of 1.25 bar.

8 1. Switch off system (select System -> END) and press service switch S1 inPDC_A (Service Push-Button S1 in PDC-A / p. 11).

2. Switch off rotation enable switch S301.3. Remove HV plugs from the HVT (high voltage tank).

4. Check HV plugs and the 2 silicon disks for signs of arcing (black dots orstripes) (HV plugs with arcing tracks / p. 26).

a) If there are any signs of arcing -> continue with item 9

b) If there are no signs of arcing -> continue with item 10.

9 • If there are any signs of arcing on the plugs or the disks.

a) Clean HV plugs and HVT sockets inside with alcohol

b) If any signs of arcing (e.g. cracks) remain on the HV cable plugs or HVT

sockets -> change the relevant part(s).

c) If there are no signs of arcing remaining on the parts -> reinstall HV plugsinto HVT using new silicon disks.

d) Try scanning again -> if the HV problems reoccur continue with item 10.

10 • Perform HVC plug test scans with installed dummy plugs (#1621791) at HVT (HVC plug test / p. 30). Follow the dialog of the HVC plug test.

a) If there are no XRS error messages found in the logbook (UMAR errorsare acceptable) -> change both HV cables including the HV sockets.

b) If there are XRS error messages found in the logbook -> change HVT.

11 • The HV problem is related to tube load.

Possible reasons: Inverter problem, ground problem, HVT.

a) Check Eventlog for XRS errors related to inverters -> if there are any fol-low the instructions given in the error message.

b) Check ground connections (bad contact....) of the XRS parts.

Step Action

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24 XRS



NOTE From 11/2009 on, new tubes need a pressure of 1.25 bar (+altitude correction). These tubes are clearly labelled, andalso the expansion unit is labelled with a red sticker.

Set the pressure on “old” tubes without label to 1.05 bar, andon newer tubes to 1.25 bar according to the label.

The expansion vessel for the following measurement can be ordered from service stock.The part number for the vessel is: 10569439.

• Cool down the system for at least 10 minutes cooling time after the last scan. Duringthe cooling time, the system must be switched on.

Be aware that some system components may be very hot, e.g., the Straton tube,

XTC, etc. may reach up to 130 degrees Celsius.• Wait until the tube and the cooling system have cooled down, then switch the system to

COMP/ON status at the control box.

• Switch off the gantry power using service push button S1 in PDC A.

• Remove the gantry lower front ring segment.

• Turn the gantry by hand until the Straton MX P tube (A or B) is in the 6 o‘clock position.

• Secure against unintended rotation by using the front safety bolt.

• Prepare the expansion vessel.

• Open the quick coupling and disconnect the lower oil hose at the tube. Connect the oilhose from the expansion vessel to the empty quick coupling of the tube.

Fig. 9: Adjusting unit for expansion membrane

• Install the adjustment handle (item 1) on the expansion vessel.

- Press the button (item 2) to lock the thread rod on the membrane.

- Hand-tighten the 2 screws of the adjustment thread rod (item 3).

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XRS 25


NOTE The pressure indicator at the expansion vessel shows theactual pressure in the oil circuit after the oil hose from expan-sion vessel has been connected.

• Check/adjust the oil pressure.

Fig. 10: Adjusting the tube pressure

• Check the pressure at the pressure indicator (item 2) attached to the expan-sion vessel using the expansion handle (item 1).

The correct pressure for tubes without a label is 1.05 bar +/- 0.05 bar at20°C at sea level. See following table for altitude correction of pressure.

Newer tubes are clearly labelled with a sticker that requests a pressure of1.25 bar at sea level.

See following table for altitude correction of pressure.

• If the system is located at a higher altitude than sea level > add the followingcorrection factor to the sea level pressure (see following table)

For example, Potosi (Bolivia) is located at an altitude of 4000m.If an “older” 1.05bar tube needs to be adjusted there, the correct pres-sure would be 1.05bar + 0.39bar = 1.44barIn Mexico City (Mexico, altitude 2300m), the same tube would beadjusted to 1.3 bar, and in Hamburg (Germany, app. sea level) it wouldbe 1.05bar.

Likewise, for “newer”1.25bar tubes, the correction factor has to be con-sidered.

Altitude [m] Difference [bar]

0 0.00

500 0.06

1000 0.12

1500 0.17

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26 XRS



• Unlock the safety bolt for gantry rotation.

• Rotate the gantry by hand and check for unusual noise.

• Close all covers opened before.

• Switch on circuit breakers F2, F3, F5, F6, F7, and F11 in the PDC A and F2 in the PDCB.

First switch the F2, F3, F5, F6 circuit breakers to the “0” position and then to the“1” position.

• Switch the system to the SYSTEM/ON status at the control box.

HV plugs with arcing tracks 0

HV plugs and insulators with arcing tracks

Fig. 11: HV plug with signs of arcing

2000 0.22

2500 0.27

3000 0.31

3500 0.35

4000 0.39

4500 0.43

5000 0.47

• If the pressure is not correct, adjust the membrane position using the adjust-

ment handle (item 1).• After the pressure adjustment is finished, remove the expansion vessel

(remove the oil quick-snap connection to the XRT).

• Attach the second oil hose from the XTC again to the tube.

Altitude [m] Difference [bar]

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XRS 27


Fig. 12: HV plug with signs of arcing

Fig. 13: HV insulator with signs of arcing

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28 XRS



HV plug installation at HV sockets 0

1. Prepare the high voltage connectors and test plugs.

Fig. 14: Silicon oil on HV plugs

Fig. 15: Silicon oil on HV plugs

• Check to ensure the connector is clean and inspect it for damage.

• Apply oil (supplied with the part) to the entire plug surface (left figure, item 1).

Use about half of the oil from the tube for both plugs.

• Put oil into the new silicon insulator (item 2).

• Install the silicon insulator part over the plugs (left figure, item 1)

Ensure there is no air left in the silicon insulator.

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30 XRS



HVC tube test

For high tension arcing or HV breakdown, the test utility HVC tube test is available in the“Tube/Generator” test tools platform. The HVC tube test lets you apply high tension to theHV circuit without tube current. No test plugs are used in this test. No radiation is released

during the test procedures. This test should always be performed before an HVC plug testis started. If this test does not indicate an error, the HVC plug test will not indicate an erroreither. This may lead to wrong part replacements.

Prerequisites

Test needs system in standby status.

Performing the HVC tube test

1. Select Local Service -> Test Tools -> Generator --> HVC tube..

2. Select Ttube A or B.

3. Click “Go” on the virtual user panel. Follow the instructions in the dialog.

4. Click the Start button at the control box.

The test runs for 80 seconds. The test is terminated automatically with an error mes-sage from UMAR (scan time exceeded).

If test fails perform the HVC plug test described next to select which XRS part isdefective.

HVC plug test

For high tension arcing or HV breakdown, the primary test utility HVC plug test is available

in the “Generator” test tools platform. The HVC plug test lets you apply high tension to theHV circuit without tube current. This allows the HV circuit to be systematically reducedusing 2 types of test plugs to isolate a high tension fault to either the Straton MX tube, HVtank, or the HV cables. No radiation is released during this test procedure.

Prerequisites

• Dummy plugs (mini type) -> part no.10 093 700 types for plug into the HV sockets.Delivered with the system.

• Dummy plugs (normal type) -> part no. 16 21 791 types for plug into the HV tank .

NOTE The HVC plug test is only allowed with test plugs installed.Tests with the installed tube can result in misdiagnosis offailures. For the installed tube, use the HCV tube test instead.

Performing the HVC plug test

1. Install the relevant test plugs in the HV sockets (front) or HVT.

a) Switch off system (select System -> END).

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XRS 31


b) Press service switch S1 in PDC_A (Service Push-Button S1 in PDC-A / p. 11).

c) Open the gantry covers as needed.

d) Disable gantry rotation with switch S 301.

e) Remove HV plugs and install the test plugs.

HV sockets at front: When installing test or HV plugs, new insulators mustbe used.

HVT sockets: When installing test or HV plugs, new silicon disks must beused.

f) Switch system on (S301 remains switched off).

S301 has to be switched off because during Init the Rot FW searches for anindex pulse. This may result in a 360 degree rotation of the gantry. In thiscase the removed HV cables may damage parts in the gantry.

2. Select Local Service -> Test Tools -> Generator -> HVC plugs.

3. Select HVC plug A or HVC plug B test.4. Click “Go” on the virtual user panel. Follow the instructions in the dialog. Important work

steps are listed below:


The test runs for 80 seconds. The test is terminated automatically with error messagefrom UMAR (scan time exceeded).

-> If the test fails, follow the HV troubleshooting guide (High voltage / p. 21).

NOTE New silicon insulators at the HV sockets (HV plug installation

at HV sockets / p. 28)) as well as new silicon disks in the HVThave to be used for the HV cable and test plugs before theplugs are installed into the components (HV sockets / HVT).

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32 XRS



Filament 2.4

TSG filament 0

The filament function is tested during “Init” (e.g., COPMP/ON -> SYS/ON). After switchingthe gantry off/on, a self-test of the D770 (FIL power) in XGR is performed as step 1. In step2, a filament current is sent to the filament heating in the XRT (X-ray tube), passing the fil-ament transformer at XRT. If the self-test fails, the error message XRS_111 (XGR FIL Self-test Error) is sent to the logbook.

Additionally a test utility "FIL" is available in the "Tube/Generator" test tools platform. Duringthe "INIT" filament test, the involved D700/D770 board components in the XGR and the fil-ament current to the XRT are tested (only in/out test). With the "FIL" test, the involved fila-ment components and the filament regulation function are tested. So the "FIL" test is amore detailed test option.

Remark: Test can be used if system is in or is not in standby status.

Tab. 3 Filament test

Filament 0

Filament test

This test checks the function of the filament power board (FIL-Power) in XGR box, the cableconnection to the XRT, the filament transformer at XRT, and the filament heating in the tubeitself. No radiation is released during this test procedure.

Performing the filament test

1. Select Local Service -> Test Tools -> Tube/Generator.

2. Select FIL


Step Action

1 • Switch gantry off/on using the control box (COMP/ON -> SYS/ON) to per-form an XGR INIT

2 • Check in the EventLog for the error message CT_GSA/GRA_20 (XGR FILSelftest Error).

-> if the error message was sent to the logbook during INIT -> follow the trou-bleshooting instructions given in the error message.

-> if the error message was not sent to the logbook during INIT -> continuewith item 3.

3 • Perform the "FIL" test function.

-> if the "FIL" test fails -> change 1. XRT and 2. XGR assembly

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XRS 33


Anode rotation (RAC) 2.5

TSG Anode Rotation (RAC) 0

An RAC frequency test function is available beginning with VA20. Use this test function toverify the RAC function. There are different anode speed (Hz) selections possible. In thetroubleshooting instructions below, 160 Hz is selected because this is very stressful for theRAC function (Note: Do not use this selection in quick succession to avoid overload).

An RAC extended test function is available beginning with VA20. Use this test function tocheck the rotating anode revolution with respect to the time (acceleration). The followingstatements are possible:

- No revolution -> e.g., rotating anode bearing defective, bad cable/plug connection, XGR...

- Revolution in the medium revolution range is too low -> e.g., rotating anode motor defec-tive, XGR....

- Upper revolution range not reachable -> e.g., rotating anode bearing defective, XGR...

Note: Test needs the system in standby status.

Note: Anode rotation on a Staton MX P tube may not be started without a functioning andconnected cooling circuit (e.g., for troubleshooting).

Tab. 4 Anode rotation (RAC) test

Step Action

1 • Perform AnodeRot Frequency Local Service > Test Tools > Tube/Generator> RAC and select 160 Hz.

-> if the RAC test fails -> continue with item 2.-> if the RAC test is ok -> no further action.

2 • Perform AnodeRot Frequency Local Service -> Test Tools -> Tube/Generatorand select the following RAC extended tests:

1. RAC anode movement test

2. RAC acceleration test

3. RAC maximum speed test

• If test 1 fails -> continue with item 3



3 Possible cause of error: no revolution. 1. Check cable connection W604between XGR (X6) > XTA (X2) for broken wire or bad contact. 2. Rotating anodemotor defective > change XRT. 3. XGR assembly defective > change XGRassembly.

4 Possible cause of error: revolution in the medium revolution range is too low. 1.Rotating anode bearing defective > change XRT. 2. XGR assembly defective >change XGR assembly.

5 Possible cause of error: upper revolution range not reachable. 1. Rotating anode

bearing defective > change XRT

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34 XRS



Single pulse test 2.6

Single pulse test 0

The single pulse test allows you to identify problems from the inverter assemblies up to theHV_Tank by triggering the inverters for a single pulse. Use the single pulse test after per-forming the TSG “High voltage” (High voltage tests / p. 29) as a last step or if there isIMAX/UB MAX parameter information identified in an error message. Please use a memoryoscilloscope to measure the output of the single pulse test.

Tab. 5 Single pulse test

Prerequisites

• Memory oscilloscope

Step Action

1 Perform the single pulse test (Performing the single pulse test / p. 35) with a nor-mally connected tube.

In addition to the given test result, check the UT_act value in the relevanttest message in the Eventlog.If UT_act parameter is E 0x50 0x02 0x57 0x1B 0x... 0x... 0x00 > test wassuccessful. No problem on inverter part.If UT_act parameter is E 0x50 0x00 0x4D 0x09 0x... 0x... 0x00 > test wasnot successful. Continue with item 2.

2 Perform single pulse test (Performing the single pulse test / p. 35) with installedtest plugs (#1621791) (HVC plug test / p. 30). Follow the dialog of the HVC plugtest to install the test plugs

In addition to the given test result, check the UT_act value in the relevant

test message in the Eventlog.If UT_act parameter is E 0x50 0x02 0x57 0x1B 0x... 0x... 0x00 > test wassuccessful > X-ray tube problem > exchange X-ray tube.If UT_act parameter is E 0x50 0x00 0x4D 0x09 0x... 0x... 0x00 > test wasnot successful. Continue with item 3.

3 Compare the output diagram of the scope, the enclosed example diagrams andtolerance values shown below.

The time for a single pulse has to be 9 microseconds +/- 20%.

The current should have a peak value of +170A +/- 20% or -170A +/- 20% (alter-nating).

The tube voltage (UT_act) should have a peak value above 10 kV.

If the current is too high and/or the tube voltage is too low, check theMVT and HVT cabling (short circuit)

If cabling is o.k. > replace parts in the following order:1. MVT2. HVT3. Relevant inverter

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XRS 35


Performing the single pulse test

1. Move the XGS_Control assembly out of the PDC to get better access.

NOTE The power at the XGS control is 24 V and 5 V. Do not touch

any parts on the XGS control. Connect the probes only asdescribed below.

To get better information, it is recommended to use a 3 chan-nel scope as described below. If only a 2 channel scope isavailable, measure UT_act first and then I_load to get thenecessary information.

2. Connect scope:

- Channel 1

- XGS D701 > X211 UT_act (1 V = 20KV)

- ANA_GND > XGS D700 > X87

- Adjust scope to 1 V/div

- Channel 2

- XGS D701 > X5 I_load (1 V = 50A)

- ANA_GND > XGS D700 > X87

- Adjust scope to 1 V/div

- Channel 4

- XGS D700 > X104 N_Start_inv

- GND > XGS D700 > X112

- Adjust scope to 5 V/div3. Adjust scope

- Time base 20 microseconds

- Trigger channel 4 (neg. slope, single)

4. Select Local Service > Test Tools > Tube/Generator

5. Select Unset all in the generator application.

6. Select Single Pulse

7. Press the Start button on the virtual user panel.

The test is terminated automatically.

The time for a single pulse has to be 9 microseconds +/- 20%.

The current should have a peak value of +170A +/- 20% or -170A +/- 20% (alter-nating).

The tube voltage (UT_act) should have a peak value above 10 kV.

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36 XRS



Single pulse test diagrams 0

The first 2 images are good examples; the last 2 images are error examples.

Fig. 19: Single pulse test diagram

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XRS 37


Fig. 20: Single Pulse test diagram

Error examples

Short-circuit at the oscillating current cable (MV cable) in the HV tank

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38 XRS




Short-circuit at inverter output


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XRS 39


Arcing 2.7

The “Arcing” test is used from the lab to simulate arcings to verify that the FW/SW reactiondue to arcings is correct. This test is not service-relevant.

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40 XRS



XRS hints 2.8

This is a summary of troubleshooting hints obtained from experience.

Tab. 6 XRS hints

Step Action

1 The XGS_PDC control assembly A/B are identical. XGS_PDC control A assem-bly controls the complete switch-on process of most system parts. If this partbecomes defective, the system components will not switch on. For trouble-shooting and to ensure that the system components are switched on again(in case control assembly A is defective), exchange the XGS_PDC control Ain PDC_A with XGS_PDC control B in PDC_B.

1. Exchange XGS_PDC control A in PDC_A with XGS_PDC control B inPDC_B in accordance with the “Replacement of parts PDC” instructions.After replacement, the guided tour for replacing parts has to be performed

for the XGS_PDC_Control.

2. Always install the Dongle plug (including the 120 ohm CAN bus resistor) atXGS_PDC control B plug X3.

2 The inverter 1 and inverter 3 cable connections can be exchanged for trouble-shooting (both inverters are identical).

1. Remove inverter plug X23 (inverter 1) and X43 (inverter 3) from theXGS_PDC_Control backplane.

2. Install inverter plug X23 (inverter 1) in the X43 backplane plug and X43(inverter 3) in X23 backplane plug on the XGS_PDC_Control backplane.

If the error moves with the inverter -> inverter is defective. If the error does not move with the inverter -> inverter and inverter

cable ok, check for other problems such as the cable connection,ground connection, or check for other error messages producedalong with the inverter error message. Follow the instructionsgiven in this message.

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XRS 41


Switching on status display of XGS 2.9

The seven-segment display on XGS board D700 (see image below) indicates the XGS sta-tus from switching on the system up to scan execute. The status information of the displayis to be used to obtain information as to the system state when a problem occurs. This infor-

mation can be used for troubleshooting.

Fig. 23: D700 measuring points and LED status

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42 XRS



Fig. 24: XRS Status

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XRS 43


Measuring points 2.10

Measuring points D700, D701, D702, D703 0

D700 measuring points

Fig. 25: D700 main board

Tab. 7 Oscillating current measuring points

Tab. 8 Oscillating current and dose act. measuring points

item signal name short name validat

description measur-ing point

1 I_load_MVT I_L_MVT XGS oscillating current MVT (sec-ondary) 1 V = 50 A.

X66

1 I_load_INV5 I_L_Inv5 XGS oscillating current Inverter 5 / 1V = 50 A.

X67



2 I_load_INV3 I_L_Inv3 XGS oscillating current Inverter 3 / 1V = 50 A.

X77

2 Dose_act Dose_act XGR actual dose value from fast link1 V = 13.107 value

* other similar values withD703 Fastlink control registerselectable.

X76

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44 XRS



Tab. 9 Voltage supply measuring points

Tab. 10 Ground measuring points

Tab. 11 HW interrupt for ignition pulses main inverter

Tab. 12 Tube voltage measuring points



3 P15V P15V XGS +15 V Voltage supply X69

3 N15V N15V XGS -15 V Voltage supply X71

3 UDC UDC Intermittent voltage X73

3 VCC VCC XGS + 5 V Voltage supply X75

3 ANA_GND ANA_GND XGS analog ground X78

3 GND GND XGS ground X80

item signal name short name validat description measur-ing point

4 VCC VCC XGS +5 V voltage power supply X75

4 ANA_GND ANA_GND XGS analog ground X78



5 S1 S1 XGS Ignition switch: HW interrupt of

the ignition pulses from themain inverter. Normal positionis off - V162 must be off. Nofunction in XGR. Normal posi-tion is off.

n.a



6 P_UT act P_UT act XGR positive tube voltage 1 V = 10

kV.

X81

6 N_UT act N_UT act XGR negative tube voltage 1 V = 10kV.

X83

6 UT_act UT_act XGR Tube voltage 1 V = 20 kV. X85

6 ANA_GND ANA_GND XGR analog ground . X87

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XRS 45


Tab. 13 IT act. measuring points

Tab. 14 Service switch

Tab. 15 IT act. measuring points

Tab. 16 FPGA voltage measuring points

Tab. 17 FPGA voltage measuring points



7 MA_meas_1 1 XGR IT_act measurement point 1

for ampere meter.

X61

7 MA_meas_2 IT_nom XGR IT_act measurement point 2for ampere meter.

X59

Item Signalname

short name validat

Description Measur-ing point

8 S5 S5 XGR Switch must be on for IT_actmeasurements using a

ampere meter at measuringpoints X46, X48, X50, X59,X61. LED V202 is on if switchis activated. Normal position isoff.

n.a



9 IT_act IT_act XGR actual tube current X48

9 IT_nom IT_nom XGR nominal tube current X50

9 ANA_GND ANA_GND XGR analog ground X46



10 VCC3.3 VCC3.3 XGS +3.3 V I/O voltage FPGA X20

10 VCCINT VCCINT XGS +1.5 V core voltage X44



11 S2 S2 XGSXGR

Service switch: Switch has nofunction at this time. Neverthe-less, switch must be in off posi-tion. LED V6 must be off.

n.a

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46 XRS



Tab. 18 FPGA digital out

Tab. 19 FPGA digital out

D701 HVC board measuring points

Fig. 26: D701 measuring points

Item signal name short name validat


12 N_Start_FIL

_INV

FIL XGR Start FIL inverter (low active).

Can only be used in XGR.

X100

12 N_Start_RAC_INV

RAC XGR Start RAC inverter (low active).Can only be used in XGR.

X102

12 N_Start_HV_INV

INV XGS Start HV inverter (low active). X104

12 XC XC XGS XC signal (X-ray request) X106

12 XRAY_on XRAY XGS XRAY on signal (> 20 kV) X108

12 INV_Fault Inv_err XGS Summary error HV inverter

Can only be used in XGS.

X110

12 GND GND XGSXGR

Ground X112

Item signal name short name description measur-ing point

13 S3/S4 n.a Dip switches for debug and configura-tion of the FPGA - not for service use.

n.a

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XRS 47


Tab. 20 D701 HVC board measuring points

D702 FIL/RAC board

Tab. 21 D702 FIL measuring points



1 UT_act UT_act XGS Actual tube voltage (from rotat-

ing part over fast link) 1 V = 20kV

X211

1 U_control U_con XGS Set value for kV regulator X216

1 I_load_act I_L_A XGS Actual oscillating current. 1 V =50 A

X215

1 USTU USTU XGS Set value for kV regulator.(Voltage control cycle). -5 V ...0 V

X208

1 I_load_nom I_L_N XGS Nominal oscillating current. 1V = 50 A

X207

1 UDC_act UZ_act XGS Actual intermediate circuit volt-age

X210

1 ANA_GND A_GND XGS analog ground X209

1 I_load I_load XGS Oscillating current. 1 V = 50 A X5

1 UT_nom UT_nom XGS Nominal tube voltage X204


1 USTI USTI XGS Set value for kV regulator (cur-rent regulator circuit) 0 .... 5 V X203

1 Upre_con Upre XGS Set value for kV regulator (pre-liminary control) 0 ... 5 V

X201



description mea-suringpoint

D702 IT_act IT_act XGR actual tube current

max. 80 mA -> 1 V = 100 mA

<80 mA -> 1 V = 80 mA

X18

D702 IF_act_1 IF_act_1 XGR actual filament heating 1

1 V = 0.273 A

X19


1 V = 0.273 A

X20

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48 XRS



Tab. 22 D702 RAC measuring points

D732 HV acquisition

HVT (high voltage tank) measuring points

Tab. 23 D732 HVT measuring points


1 V = 0.273 A

X21

D702 ANA_GND A_GND XGR analog ground X17

board signal name short name validat

description mea-sur-ingpoint

D702 Test_DAC_1 DAC_1 XGS FPGA controlled debug DAC X10

D702 Test_DAC_2 DAC_2 XGS FPGA controlled debug DAC X11

D702 Res_sin sin XGS Resolver Sine Signal X12

D702 Res_cos cos XGS Resolver Cosine Signal X13

D702 RAC_P3 P3 XGS RAC Strom Phase 3(1 V = 40A, Offset 2.5 V)

X14

D702 RAC_P2 P2 XGS RAC Strom Phase 3(1 V = 40A, Offset 2.5 V)

X15

D702 RAC_P1 P1 XGS RAC Strom Phase 3 (1 V = 40

A, Offset 2.5 V)

X16

D702 ANA_GND ANA_GND XGS analog ground X17


description mea-suring

point

D732 ANA_GND ANA_GND XGR analog ground X12

D732 P_UT_act P_UT_act XGR Tube voltage (pos.) (1 V = 10kV)

X13

D732 N_UT_act N_UT_act XGR Tube voltage (neg.) (1 V = 10kV)

X14


description mea-suringpoint

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XRS 49


LED´s on D700, D701, D702, D703 0

D700 LED status

Fig. 27: D700 measuring points and LED status

Tab. 24 D700 main board

board signal name valid at description LEDs

D700 S_FIL_INV XGR Start FIL Inverter. Only used in XGR. V7

D700 S_RAC_INV XGR Start RAC Inverter. Only used in XGR. V8

D700 S_HV_INV XGR/XGS Start HV Inverter (at XGR signaldelayed due to transport (fastlink) delay.

V9

D700 Cycle LED XGR/XGS FPGA Life Cycle LED V10

D700 XC XGR/XGS XC Signal from system V11

D700 XRAY_On XGR/XGS XRAY On Signal (UT_act > 20 kV) V12

D700 INV_Err XGS Inverter Error V13

D700 FPGA_Err XGR/XGS Error Interrupt from FPGA V14

D700 MB 1000 mA XGR IT_act measurement range 1000 mA V15

D700 MB 100 mA XGR IT_act measurement range 100 mA(amplification *10)

V16

D700 MB 25 mA XGR IT_act measurement range 25 mA(amplification *40)

V17

D700 D_UT XGR Delta UT_act monitoring V18

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50 XRS



D701 HVC board


D702 FIL/RAC


D700 STOP XGR/XGS Stop Report Loop V20

D700 UT_MAX XGR UT_act max. monitoring V21

D700 A XGR/XGS System A on System B off V23

D700 rot XGR/XGS rotating on, stationary off V24


D701 LED 1 n.a not used V205



D701 LED 4 n.a HVC Error Interrupt V208


D702 n.a XGR FPGA out LED 0lim_1: Lim regulator

FIL_1 active

LED_0

D702 n.a XGR FPGA out LED 1 20peak_1: Peak regu-lator FIL_1 active

LED_1

D702 n.a XGR FPGA out LED 2 20STOP_FIL/STOP_RAC.

LED_2

D702 n.a XGR FPGA out LED 3 20RAC_State_0. LED_3

D702 n.a XGR FPGA out LED 4 20RAC_State_1 LED_4

D702 n.a XGR FPGA out LED 5 20HALL_A LED_5

D702 n.a XGR FPGA out LED 6 20HALL_B LED_6

D702 n.a XGR FPGA out LED 7 20FIL_Error_Int /RAC_Error_Int

LED_7


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XRS 51


D703 XG board


D704 dongle board

Tab. 28 D704 dongle board

D790 PDC board

Fig. 28: D790 signal LEDs

Item signal name valid at description LEDs

D703 LinkErr XGS/XGR Link Error LED[5]

D703 LightErr XGS/XGR Light Error LED[4]

D703 CfgErr XGS/XGR Config Error (FPGA not programmed) LED[3]

D703 DefCfg XGR xray_and_not_door (XGR) LED[2]

D703 RunCfg XGS door closed (XGS) LED[1]

D703 Prg XGR door closed (XGR via Fastlink) LED[0]

D703 LED 1 XGS XGS_off (XGS indication when startinginverter)

LED[6]

D703 LED 2 XGS/XGR LifeCycle (flashes if FPGA is loaded) LED[7]


D704 VCC XGS/XGR Power supply 5 V V1

D704 P_15V XGS/XGR Power supply 15 V V2

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52 XRS



Tab. 29 D790 PDC board LEDs


D790 P_24V_SNT XGS P_24V from switched power supply(only used for relays, feedback, and

fans)

V1

D790 VCC_SNT XGS VCC (5 V) from switched power supply V2

D790 VCC3.3 XGS FPGA IO voltage (3.3 V) V3

D790 LED morse XGS FPGA Lifecycle LED (if LED flashes ->FPGA is loaded and is functioning)

V4

D790 P_15V_SNT XGS P_15V from switched power supply V5

D790 VCC_INT XGS FPGA core voltage (1.5 V) V6

D790 N_15V_SNT XGS N_15V from switched power supply V7D790 P_15V_SNT

_AUXXGS P_15V from switched power supply for

inverter und fans.V8

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XRS 53


Fig. 29: D790 PDC board signal LEDs



D790 Main_Sw XGS PDC Main Switch Breaker Signal V105

D790 Cooling_CB XGS Cooling Unit Breaker Signal V117

D790 XGS XGS XGS Breaker Signal V116

D790 PHS_CB XGS PHS Circuit Breaker Signal V138

D790 Gan_Stat XGS Gantry Stationary Breaker Signal V144

D790 Gan_Rot XGS Gantry Rotating Breaker Signal V143

D790 UPS XGS UPS Breaker Signal V157

D790 Insul_Power XGS Insulation Power Breaker Signal V158

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54 XRS





D790 Cooling XGS Cooling Unit Signal V106

D790 PHS XGS PHS SignalLED off -> trigger and feedback off; LEDon -> trigger and feedback on; LEDflashing -> trigger and feedback differ-ent

V118

D790 L2_Perm_Gantry

XGS L2 Gantry Signal

LED off -> trigger and feedback off; LEDon -> trigger and feedback on; LEDflashing -> trigger and feedback differ-ent

V119

D790 Charg_XGR XGS Charging XGR Signal


V139

D790 PWR_XGR XGS Power XGR Signal


V145

D790 IRS XGS IRS Signal


V146

D790 ICS_Ether XGS ICS Signal

LED off -> trigger and feedback off; LEDon -> trigger and feedback on; LEDflashing -> trigger and feedback differ-

ent

V160

D790 Charg_XGS XGS Charging XGS Signal


V159

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D790 PWR_XGS XGS Power XGS


V107

D790 Temp_Trans XGS Temp Transformer Signal V120

D790 Power_CTRL XGS Power Control Signal V121

D790 Diff_Sw XGS Diff Switch Signal V140

D790 Volt_Prot XGS Voltage Protection Signal V147

D790 Current Loop XGS Current Loop Signal V148

D790 Door XGS Door Switch Signal

LED On: Door open (in PDC_B alwayson)

V162

D790 Fan Mode XGS Fan Mode

LED On: low noise mode (15 V)

V161

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56 DMS



3-3DMS

General 0

Safety 0





NOTE Follow ESD guidelines when handling the DMS.

Notes 0

There are 2 Types of DMS:

TACH- DMS and AMS DMS. Please check SPC for partnumbers, some spare parts arespecific for one or the other type.

Most noticeable are the colours of the handles of the modules: TACH modules have a greyhandle, AMS modules have a pink handle.

1. Before starting troubleshooting, be sure you troubleshoot the right area.

- To distinguish between the DMS’s and IRS, use the Datalink Test and check the datapath first

- To distinguish between DMS A and DMS B, run the DMS tests and check if theerrors are related to DMS A or DMS B.

- To distinguish between DMS A and DMS B, especially if image quality problemsappear in Dual source modes, it is useful to have a 30 cm water phantom (ServiceTool, also used for IEC Acceptance).

- To distinguish between module and backplane, it is possible to cross the modulecable at the backplane.

If the error moves when crossing the module cables at the backplane, the problem isrelated to the module or module cable.

- To distinguish between module and module cable, it is possible to swap the wholemodule cable with a neighboring one.

If the error moves when swapping the whole cable, the problem is related to the mod-ule cable.

NOTE A second peak may appear in the displayed plot with modulecables crossed or swapped. This is normal if no new calibra-tion (e.g. a new Checkup or Setup/Calibration) has been per-

formed prior to starting a new scan.

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DMS 57


2. If possible, use the test modes with rotation for troubleshooting especially in case ofnoise problems.

NOTE Use rotation modes with the collimations shown below andclose all DMS covers before starting rotation.

The two most useful slice combinations for troubleshooting are:

- 32 x 0.6 mm

- 24 x 1.2 mm


n.a.

Prerequisites 0

1. Check (Environmental Conditions / p. 96) (especially in case of weak rings)

2. Check for objects in the scan field e.g. contrast agent, labels,...

3. Try to reproduce an image the customer has complained about using the same param-eters

4. Use (ROI/Ring / p. 69) and note the positions as a reference for the position expectedto contain the defect (two positions are possible).

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58 DMS



TSG Image Quality 3.1

This chapter provides a basic overview of different types of image quality problems and auseful way for starting troubleshooting.

General 0

NOTE Important! There is almost no cooling of the DMS electronicsif the metal DMS cover is removed. If the DMS plastic coverremains installed, there is a risk of overheating. Alwaysswitch the gantry “off” completely prior to opening and work-ing at the DMS, to prevent damaging parts.

NOTE Most of the image quality problems are related to defective

channels within a detector module. That is why troubleshoot-ing should start with defective channel detection. This chap-ter is sorted for different types of image quality problems andshould guide you. The DMS tests are described later in thischapter.

Possible reasons for ring and band (mostly 4, 8, or 16 channels) artifacts are:

• Defective detector element

• Defective detector cable

• Defective backplane

• Insufficient calibration (e.g. contrast agent at plexiglas ring)

• Insufficient tune-up tables

• Problem with balancing (reconstruction)

• Insufficient environmental conditions

• Defective IRS

• Bands covering 16 channels might be caused by the incorrect Z-position of one mod-ule. Run Z-position check of module.

NOTE Problems related to a single slice appear as permanent rings

in sequence modes, and as partial rings in spiral scans.

Possible reasons for streak artifacts are:

• Defective detector module

• Patched channels

• Alignment adjustment

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60 DMS



TSG sporadic strong rings 0

Ask the customer to perform a Checkup in case of problems.

Start troubleshooting as follows:

3 • Compare the entries in Reports to the channels you found with ROI/Ring.

a) if entries are related to the customer image -> patch out the channel

manually. Refer to section defective channel detection.b) If no channel is related to the customer image, -> continue with step 4.

4 • Run (Defective channel detection / p. 70) in the Tune up platform.

a) if problem is solved -> Run Quality check (Quality Constancy).

b) if not o.k., e.g., too many bad channels found, -> continue with step 5.

5 • Run (Guided tour for image quality / p. 73).

a) If there are errors found in one or more tests, -> continue with step 6.

b) If there are no errors found, run (Sinogram / p. 80) for additional informa-tion.

6 • If only one channel is found to be defective, -> patch out the channel man-ually and check Reports whether the defect has remained in the sys-tem.

7 • If neighboring channels, channels in detector centers, or channels whichcannot be patched out are defective -> continue with step 8.

8 • Cross the module cable on backplane with the neighboring modulecable to distinguish between the module and the backplane.

• Close all DMS covers.

Repeat the tests which showed errors before and check if the error moves.a) If error still in initial position -> replace the backplane.

b) If error moves to neighboring slot -> module or module cable defec-tive, continue with step 9.

9 • Swap the complete module cable with the neighboring module cable to dis-tinguish between the module and the module cable.


Repeat the tests which showed errors before and check if the error moves.

a) If error still in initial position -> replace the module.

b) If error moves to neighboring slot -> replace the module cable.

10 • Additionally, check the power path.

Especially if the errors are related to an entire backplane, -> check thepower supply of the DMS. Refer to (TSG DMS Power path / p. 88)

Step Action

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DMS 61


Tab. 34 TSG

Step Action

1 • Ask the customer to save the image in case of problems.

a) The image is important for further evaluations with ROI /Ring.2 • Ask the customer to perform a Checkup in case of problems.

a) This particular (automatically generated) checkup table can be used forfurther defective channel evaluations.

3 • Use (ROI/Ring / p. 69) to determine the area of the defect in the customerimage.

4 • Check for entries of sporadic channels in Reports. Refer to section defectivechannel detection.


a) If sporadic entries are related to the customer image -> patch out thechannel manually. Refer to section defective channel detection.

b) If no channel is related to the customer image, -> continue with step 6.


a) if problem is solved, -> Run Quality check (Quality Constancy).

b) If not o.k., e.g. too many defective channels found, -> continue with step7.

7 • Run (Guided tour for image quality / p. 73).

a) If there are errors found in one or more tests, -> continue with step 8.b) If no errors are found, -> continue with step 9.

8 • If one channel is indicated as defective, -> patch out the channel manu-ally.

9 • Use Reports and check for irregularities within the tests, especially in thearea of the defect in the customer image.

• If irregularities are present, cross module cable on backplane with neighbor-ing module cable.


Repeat the tests which showed irregularities before.

a) Check reports again. If irregularities moved for 16 channels, -> replacethe module including the module cable.

b) If no difference is visible, swap back the cable and close all DMS covers.

c) Run a Checkup and check Reports for defective channels again.

10 • Contact HSC for further steps.

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62 DMS



TSG weak rings 0

A ring is visible in homogeneous areas such as the cerebrum, if the difference comparedto the neighboring channel is about 1 ppm.

In most cases we expect the stability of the element affected to be insufficient.

Tests which typically show problems in case of weak rings:

• BasCal stability

• Signal linearity


Tab. 35 TSG

Step Action

1 • Check (Environmental Conditions / p. 96)

2 • Ensure that DMS was powered on overnight.

3 • Check that the Tune-up was performed correctly (use Report function).

4 • Use (ROI/Ring / p. 69)to find out the area of the defect in the customerimage

5 • Check for entries of sporadic channels in Reports. Refer to section defectivechannel detection.


a) If entries are related to the customer image, -> patch out the channelmanually. Refer to section defective channel detection.

b) If no channel is related to the customer image, -> continue with step 7.

7 • Run (Guided tour for image quality / p. 73) and (Popcorn noise / p. 77) test.

a) Compare test outputs to channels you found in the customer image withthe ROI/Ring function.

b) If only one channel is defective, -> patch out the channel manually.

c) If neighboring channels, channels in detector centers, or channels whichcannot be patched out are defective, -> continue with step 8.

8 • Cross module cable on backplane with neighboring module cable.


Repeat the tests which showed errors before and check if errors move.

a) If error still in initial position -> swap back cable and continue with step9.

b) If error moves to neighboring slot, -> module or module cable unsta-ble/defective, continue with step 9 and step 10 prior to replacing themodule.

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DMS 63


TSG sporadic weak rings 0

In case of sporadic weak rings, perform TSG weak rings first.

Additionally, start troubleshooting as follows:

Tab. 36 TSG

TSG rings in outer slices only0

Rings visible in the outermost slices only might occur in case of collimation problems.


9 • Check the Power path. Refer to (TSG DMS Power path / p. 88)

a) If power path and DMS Power supply are o.k., -> continue with step 10.

10 • Perform Guided Table Generation in Tune up platform.

Note: Table Generations for DMS A and DMS B are performed. (approx. 2hours)

a) If still not o.k. -> contact HSC for further steps.

Step Action

Step Action

1 • Ask the customer to save the image in case of problems.

a) The image is important for further evaluations.

2 • Ask the customer to perform a checkup in case of problems.

a) This particular checkup table can be used for further basecal evaluations.

3 • Use (ROI/Ring / p. 69) to determine the area of the defect in the customer

image.

4 • Perform (BasCal Stability / p. 75). A difference between a satisfactory andunsatisfactory Basecal table will show the problem.

a) If only one channel is noted, -> patch out the channel manually.

b) If neighboring channels, channels in detector centers, or channels whichcannot be patched out are noted -> replace the corresponding mod-ule.

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64 DMS



Tab. 37 High voltage TSG

TSG Streak artifacts 0

1. Intermittent streaks tangential to a circle might be caused by a defective module


Tab. 38 TSG

2. Streaks tangential to a circle might be caused by too many patched channels.


Step Action


a) If more channels or a entire row of channels are out of tolerance, -> con-tinue with step 2.

b) If only one channel is defective, -> continue with step 5.

2 • Run (Module Z-Alignment / p. 83).

a) If out of tolerance, check the mechanical positioning of the module. Referto the replacement of parts section for instructions.

b) If in tolerance, -> continue with step 3.

Additionally run modes with 24 x 1.2 mm and 32 x 0.6 mm to check if theerror occurs at the same physical slice position.

3 • Run Z-Adjust in the Tune up platform.

a) If out of tolerance, troubleshoot the tube collimator.

b) If in tolerance, repeat defective channel detection. Additionallym con-tinue with step 4.

4 • Check slice thickness to ensure Constancy.

a) Run Quality Constancy, check results for slice measurement.

5 • Run TSG strong rings

Step Action


a) If no channel is found to be defective, -> continue with step 2.

b) If defective channels are detected, -> continue with step 3.

2 • Run (Popcorn noise / p. 77) test to isolate the defective channel.


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DMS 65


Tab. 39 TSG

3. Fine streak artifacts not correlated tangentially to any circle might be caused by incor-rect alignment.


Tab. 40 TSG

4. streak artifacts not correlated to any object might also be caused by tube arcing.


• Tube arcing

Check the tube history for this paticular scan to see if tube arcing was detected.Getter tube

TSG Dual Source problems 0

Notes:

Step Action


2 • Check if there are adjacent patched channels and continue with step 3.

3 • Check Reports for defective channel detection.

a) If “-> change” is written in Reports, replace the corresponding module.

b) If “-> change” is not written in Reports, -> continue with step 4.


Step Action

1 • Run (MTF test / p. 78) and check for tolerances.

a) If in tolerance, -> continue with step 2 and step 4.

b) If slightly out of tolerance, -> continue with step 2.

c) If results not plausible, go directly to step 3.

d) If only UHR modes (not supported by VA10) are out of tolerance, -> con-tinue with step 4.

2 • Run (Focus Alignment Check / p. 82) in the Tune up platform.

a) Continue with Focus Alignment in the Tune up platform.

Note: Continue with Focus Alignment as well if the Focus Alignmentcheck is in tolerance. If Focus Alignment fails, -> continue with step 3.

3 • Troubleshoot tube collimator (PSD) and Focus deflection.

4 • Run comb ali (UHR is not supported by VA10).

5 • Run TSG weak rings.

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66 DMS



• Image quality problems in dual source modes appear most often as a band in the areawhere the scan field of the DMS B is extended by the outer channels of DMS A. In dualsource modes the inner 26 cm of the scan field are measured by both DMS’s, the outerarea of the scan field (outside 26 cm) is measured by DMS A only. Measure the HU inthe area of the band. Especially in case of a high absorption (obese patients), a high dif-

ference in HU can be measured in the inner and outer area of the scan field.

NOTE For troubleshooting dual source problems, it is very helpfulto have a 30 cm water phantom as used for the IEC Accep-tance.

•


Tab. 41 TSG

Step Action

1 • Check if the problem is caused by one of the DMS’s, or if the problemappears only in dual source modes.

a) Run single source modes (B-modes) in the Rot mode platform and usea 20 cm water phantom. If the images are free of artifacts, -> DMS B isok . If the images show artifacts, troubleshoot the DMS B first. Refer tothe corresponding TSG in this document.

b) Run single source modes (A-modes) in the Rot mode platform and usea 30 cm water phantom. If the images are free of artifacts, -> DMS A isok . If the images show artifacts, troubleshoot the DMS A first. Refer to

the corresponding TSG in this document.c) Run dual source modes (A/B-modes) in the Rot mode platform and use

a 30 cm water phantom. If artifacts appear in the area where DMS A addsDMS B data (at 26 cm scan field), -> the problem is related to dualsource modes only. Continue with step 2.

2 • Check if the problem is caused by incorrect scatter radiation correction.

a) Run a dual source mode (A/B-modes) in the Rot mode platform withCross Scat selected (use a 30 cm water phantom).

b) Run a dual source mode (A/B-modes) in the Rot mode platform withCross Scat deselected (use a 30 cm water phantom).

With Cross Scat selected, the critical area (at approx. 26 cm) must lookmore homogeneous. If no difference is visible, the correction is wrongor not working. -> Continue with step 3.

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TSG Spatial Resolution (bad MTF results) 0


Tab. 42 TSG

3 • Run quality constancy and check homogeneity.

a) If homogeneity is out of tolerance -> Run Water Scaling for the corre-

sponding DMS (A or B).4 • Perform Guided Table Generations in the Tune up platform. Call HSC for

further advice.

Note: Table Generations for DMS A and DMS B are performed. (approx. 2hours)

a) If still not o.k. -> contact HSC for further steps.

Step Action

Step Action

1 • Run (MTF test / p. 78) and check for tolerances.

a) If slightly out of tolerance, -> continue with step 2.

b) If results not plausible, continue directly with step 3.

c) If only UHR modes (not supported by VA10) are out of tolerance, -> con-

tinue with step 4.

2 • Run Foc. Align. check in the Tune up Platform.

a) Continue with Focus Alignment in the Tune up Platform.

Note: Repeat Focus Alignment as well if the Focus Alignment check is intolerance. If focus alignment fails, -> continue with step 3.

3 • Troubleshoot the tube including the tube collimator and the regulation circuit.

4 • Run Comb Ali in Tune up platform (UHR not supported by VA10).

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• Windmill artifact

If you browse through a stack of images, the image contains an artifact that moves likea windmill. It is especially visible at the edges of bones.

Windmill artifacts occur due to undersampling or interpolation.

Compare the pitch used with the Siemens default values.

Check if the reconstructed slice width is 1.25 times the collimated slice width.

Involve Applications in troubleshooting

• Artifacts due to patient positioning or use of positioning aids. (mainly streaks)

Head:

Check to see if the correct head holder was being used.

Body:

When using the CT-slicker, bend the edges down and glue them to the table

Tests for Image Quality 0

This chapter provides a list of all software tools available for handling DMS problems.

ROI/Ring

Scope

• The ROI function (region of interest) is used to calculate the mean value and the stan-dard deviation of a user-defined area.

• The Ring function shows the correlation of a position in an image to 2 possible chan-nels in the DMS that have been involved in creating data at that position.

How to find

• Options > Service > Local Service > Test Tools > ROI/Ring

How to use

1. Select the desired order for sorting the images in the list box by activating the corre-sponding radio button. (You may have to wait.)

2. Mark the image of your choice in the list box. Select the image by double clicking or usethe Load Loid Button.

The image will be displayed

The Button Switch to File Chooser enables loading of images from different locations.

3. Select the radio button Ring

4. Use the left mouse button to move the ring to the desired position.

Use the center mouse button for windowing.

Read out the 2 possible channels (channel1, channel2) causing the problem.

Use this information as the basis for additional troubleshooting.

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Defective channel detection

The software automatically detects bad channels.

The center of DMS A and the first and last slot (used for air slice normalization) have to bewithout defective channels. In all other slots a certain amount of defects is allowed.

1. Check for allowed defects under Reports

NOTE If you find “=>change” within the Reports, the defect cannotremain in the system and the broken part has to be replaced.Test DMS to find out if the module is really broken.

Using the Report function:

Options > Service > Local Service > Reports > Tune Up > Table Generations

- Def Chan. Cust.

Shows status of last defective channel detection during checkup.

- Def. Channels

Shows status of last defective channel detection during tune-up.

- Options > Service > Local Service > Reports > Def. Chann. History.

A history of all channels that have been patched or unpatched is shown.

- check affected modules. =>change : indicates that the corresponding module hasto be exchanged.

- If a sporadic defect within the reports corresponds to the customer image, patch outthe channel manually. Refer to “editing the correction tables”.

- Check the affected modules again after patching to determine whether the moduleis allowed to remain in the system. (=>change : indicates that the channel/channelscannot be patched out and the corresponding module has to be exchanged.)

- If no defect corresponds to the customer image, run automatic defective channeldetection in the Tune-up Platform. Refer to “Defective channel detection in tune upplatform” (item 3)

2. Performing Defective Channel Detection in the Tune-up Platform

- Select Local Service > TuneUp > Expert Mode > Defective Channels.

- Remove all absorbers.

- Select (DMS A/DMS B or both) under Select Scan Mode.

- Click Auto.

To repeat automatic detection in case of unstable / implausible results, repeat theprocedure with the auto button.

- You will be asked to accept the current calibration.

- Click Save.

The IRS tables are transfered to the IRS.

If you click Cancel, no modifications to the tune-up and IRS tables will be stored.

- Check Reports to determine whether a defect has been found and sucessfullypached out.

- The program is not sensitive enough to detect all kinds of defects. If a defect is notfound during the procedure, the DMS tests are necessary.

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NOTE If a defect was found and sucessfully patched out during theprocedure, the images must be free of artifacts now.

3. Editing the correction tables

- Select Local Service > TuneUp > Expert Mode > Defective Channels.

- Click the button for the corresponding DMS. (A or B)

- Click the button for the desired detector slot (1- 42 for DMS A) or (1 to 22 for DMS B).

Hint: A segment containing unsatisfactory elements is marked in red.

- After a while, the user interface will show the corresponding channel / slice matrix.

Now select the desired channel and slice. Select the element with the left mouseand click it. The color will change from green to red.

Left-click to remove an unsatisfactory channel entry. The color will change fromred to green.

- Click save after modifications.

- Continue, if necessary, with Correction Tables > TuneUp > 24x1200.

- Click save after modifications.

- For additional information regarding defective channel detection, refer to (Hints fordefective channel detection / p. 97).

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Common for all tests which provide a plot function

Fig. 30: Example of Relative Signal Value DMS A in error condition

• Common for all tests which provide a plot function for the results:

- The button Show Plot shows the graphical output of the table.

Select all slices via Show All, none via Hide All, or a single slice via the list box.

Zoom in (or out via Survey) using the left mouse button. Mark the area of interestwhile holding down the left button. Then press Zoom In .

Position the cursor at the desired location and wait for the display of:

- channel

- slice

- value at that position

The button Statistic displays the following for all slices: Minimum, Maximum, Mean,and StdDev.

The min. and max. values are shown only if the checkbox Y-Auto Scale is notmarked.

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How to use

1. Select the desired mode (DMS A/DMS B or both).

2. Press Go

3. Wait for the result Replace modules that exceed the threshhold

4. Description of the result page

The results of the test are shown in two tables:

- Offset value

- Offset noise

Both tables show Slice, Minimum, Maximum and Test Result.

Use the Show Plot button to display the plots.

Signal value

Scope

• This test is used to check the mean values and noise with X-ray.

Different collimations are used.

How to find (if not using the guided tour)

• Options > Service > Local Service > Test Tools > DMS > Signal Value

How to use

1. Select DMS A/DMS B or both in the platform.

2. Wait for Press START key to appear and then press the Start button.

3. Description of the result page

The results of the test are shown in three tables:

- first table: Relative Signal Value

The result shows the averaged signal of the channels in relation to the neighborhood.

This table shows Slice, Minimum, Maximum, and Test Result.

- second table: Relative Standard DeviationThis table shows Slice, Minimum, Maximum, and Test Result.

In addition, the monitor value is shown.

- third table: Absolute Signal Value

This table shows Slice, Minimum, Maximum, and Test Result.

In addition, the monitor value is shown.

Common for all tables is:

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- The button Show Plot graphically displays the table.

It’s possible to select all slices via Show All, none via Hide All, or a single slice via acheckbox. It’s also possible to Zoom In (or out via Survey) by using the left mousebutton. Mark the area of interest while holding down the left button

The button Statistic displays the following for all slices: Minimum, Maximum, Mean,and StdDev.

The check box Y-AutoScale allows automatic scaling of the Y-axis.

- For values out of tolerance, slice and channel are output.

Click the channel number and read out: Channel xxx and Slot xx.

- The button Extract to file is used to store the result of the test to disk.

BasCal Stability

Scope

• The main function of the BaseCal stability test is to subtract the last two BaseCals ofone given mode in order to find unstable channels.

The structure of the BaseCal names is:

basecal_slice_ tube voltage_ scantime_ focus size_algorithmn_organ_focus type.

They are stored in c:\Somaris\service\datastore\icstables


• Options > Service > Local Service > Test Tools > Sys. Test > BasCal Stability

How to use

1. Select DMS A/DMS B or both in the platform

2. Use the BaseCal corresponding to the mode the customer is complaining about.

3. Press Go

The result page is shown.

Before exchanging modules, compare the result with the results of ROI/Ring toverify whether the customer’s image problem has been located.

4. Activate Show Plot

Evaluate the plotIn addition to the standard functions, you can define the Segments which shouldbe shown.Hint: A BaseCal is referred to as a 360 degree rotation and is divided into 10angular segments.

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Signal linearity

Scope

• This test performs two scans with different tube currents (100mA and 300 mA).

Subtracting the mean values of these scans shows the deviation caused by the signalnon-linearity.

In addition, you may use phantoms in the scan field to check the low signal linearity.


• Options > Service > Local Service > Test Tools > DMS > Signal Lin.

How to use

1. Wait for the Press START key to appear and press the Start button

The test result page is displayed.

In case channels are out of tolerance, change the corresponding module.

2. Press Show Plot

The plot is displayed

Assignment test

Scope

• The assignment test is an internal addressing test of the DAS Controller.


• Options > Service > Local Service > Test Tools > DMS > Assignment

How to use


2. Wait for the Press START key to appear and then press the Start button

Wait for the result page

3. ActivateShow Plot

A continuous staircase from upper left to lower right should be visible for all slices.Hint: In addition to the standard function, you can define:- Segments (frames) and- FFS 1, 2 or all

4. Interpretation of the result

The possibly defective part may be:

- defective detector module

- defective backplane

- defective DAS Controller

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4. Select "upper threshold" (use default values first).

5. Select "number of measurements".

6. Select "test with or without rotation".

Start troubleshooting with rotation

7. Press Go

Check results to find channels that lie outside the threshold.

Lower the value for the upper threshold from 100 to 50, 30, and 20 to get the worstchannel output.

MTF test

Scope

• The MTF (Modulation Transfer Function) shows the spatial resolution at high contrast.

For this purpose, a 0.22 mm tungsten wire phantom is used.

How to find

• Options > Service > Local Service > Test Tools > Sys. Tests > MTF-Test

How to use

• Follow the program output.

If a value is out of tolerance, it is indicated by a “>” sign.

Offset image

Scope

• The offset image is calculated from an offset-corrected raw image added to a syntheticdisk. The raw image is acquired without radiation.

As a result, the artifacts visible in the offset images are not related to the X-ray or theUFC of the detector. Instead they are primarily related to the electronics of the integra-tor section.

NOTE The offset images may have ring artefacts. Therefore the off-set images cannot be used for evaluation or decision toreplace DMS parts.

How to find

• Options > Service > Local Service > Test Tools > DMS > Offset Image

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How to use

1. Select “Set System A” or “Set System B”

2. Select the radio button for rotation “on” or “off”.

Start testing with rotation.3. Select a scan time.

Start with the scan time the customer is complaining about.

4. Press Go and wait for the result

The offset images are calculated.Images have to be without rings, bands, or streaks.Check images with window 550 and center 0.In case of problems:

Continue with the Offset value.

5. Select radio button “images are correct" (or not correct).6. Interpretation of the results:

The images must show a homogeneous noise structure and must be without:

- Rings or partial rings

- Streaks

- Any other visible structures.

NOTE The offset images will be stored under Service patient. Theoffset measurement will be aborted in case of an active

patient.

Spectral linearity

Scope

• This test performs two scans with different tube voltages (120 kV and 140 kV).

Subtracting the mean values of these scans shows the deviation caused by the spec-tral non-linearity.

The result of this test shoud be used only in addition to other tests to confirm a chan-

nel as satisfactory or unsatisfactory.

• This test is normally used in the factory only.

How to find

• Options > Service > Local Service > Test Tools > DMS > Spectral Lin.

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How to use


2. Wait for the Press START key to appear and then press the Start button.

The test result page is displayed. If there are channels out of tolerance, call CS HSC.

3. Press Show Plot

The plot is displayed.

Sinogram

Scope

• The output of the sinogram is an image showing all channels at the X-axis as well as all

frames (projections) at the Y-axis.• Raw data sets of air scans and of scans made with a homogeneous absorber can be

evaluated.

NOTE If rotstatic.raw should be evaluated, ensure that “TransferRaw Data” was selected in the Rot/Static Platform. Other-wise, the rotstatic.raw file is not available in the Sinogramplatform.

• The sinogram is a useful tool for locating weak rings

How to find

• Options > Service > Local Service > Test Tools > Sinogram

How to use

1. Mark a file in the list box Raw Data Files.

2. Mark or unmark the checkboxes for Convolve with Kernel and Median filtering .

Start with the marked checkbox for Convolve with Kernel.

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4. Interpretation of results:

- A vertical line shows up in all frames if a channel is defective.

- A vertical dotted line shows up if a channel is defective but not throughout all frames.

- A horizontal line shows up if a frame is defective (projection).

- A dot shows up if a channel is defective in one frame.

- A sine wave shows up if a stationary absorber is located in the scan field.

(Absorber is not moving with DMS)

Tube Collim. Check

Scope

• This test checks the correct opening width and Z-position of the tube collimators. IRStables are used, which have been generated during air calibration. No scans are per-formed during this check.

How to find

• Options > Service > Local Service > Tuneup > Expert Mode > Tube Collim. Check

How to use

1. Press Go

2. Wait until the message “Tube collimator Check completed” appears.

If the result is out of tolerance

→ Perform a tune-up. Follow the guided tour for Tube Collimator→Troubleshoot the tube collimator and the regulation circuit (UMAR).

Focus Alignment Check

Scope

• This test uses the ball phantom to check if the electromagnetic focus deflection (flyingfocal spot) in PHI and in Z-position is working properly.

How to find

• Options > Service > Local Service > Tuneup > Expert Mode > Foc.Align.check

How to use

1. Select System A / System B or both in the platform.

2. Press Go

3. Select and insert phantom.

4. Press Go

5. Wait for the Press START key to appear and then press the Start button.

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4. Press Show Plot

The following plot shows well aligned modules.

Fig. 32: Module Z-alignment

5. Check if there is a drop of 16 channels (use the Zoom function), especially at the posi-tion where you performed repairs.

If yes, loosen the module exchanged previously and press it toward the rotating plane

while you are fixing the situation. Repeat the test.

Analyze

Scope

• Analyze is a versatile tool, used to evaluate raw data as well as header data.

The following functions are useful for field services:

- Integration time

- Dose monitor

- DMS Temperatures

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- Raw Data Frequency Analysis

How to find

• Options > Service > Local Service > Test Tools > Analyze

How to use

• Using the macros under Special

1. Select the radio button ICS-RawData

2. Mark the desired raw data set in the list box

3. Press Go

View is automatically selected and the plot appears.

4. Select Special

5. Mark the desired checkbox

- ReadingNo

- TubeAngle

- MaximumValue

- ErrorInfo

- CRC Error

- IntegrationTime

- Dose monitor

- DMS-Temperature 1- DMS-Temperature 2

- DMS-Temperature 3

- DMS-Temperature 4

and press Go

The corresponding curve is displayed.

• Using the raw data frequency analysis under Analyze

- Load an A or B static mode with 2 x 1.0 mm.

- Perform 2 scans of that mode and use the second one

- Open an additional window.

- Start Options > Service > Local Service >TestTools > Analyze

- Select ICS-Rawdata mark rotstatic.raw and press Go.

- Select Tools

- Select Raw Data - Frequency Analysis and press Go

- Select the channels

Start with 305 to 368 at DMS A.

- Do not select the checkbox for fusing the slices.

- Do not select Separate FFS

- Select all slices

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As shown in the example, press Go and zoom the result, if necessary.

The X-axis shows the frequency, and the Y-axis shows the amplitude.

Fig. 33: Example of raw data frequency analysis

The amplitude at the first peak (here 120 Hz) shows the quality of anode rotation(wobbling anode). A peak does not necessarilly mean that the tube has to be

replaced. Check also for tube arcing and other errors related to the tube. The amplitude at the first harmonic shows the quality of the emitter (tube).

NOTE In addition to this test, the tube has to be checked beforemaking the decision to replace it.

Send the plot to CS HSC for additional evaluation.

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Band assessment tool

Scope

• This test performs automatic test scans and runs an algorithm to find ring structures in

water phantom images. The disadvantage is that only the range of the phantom ischecked (20 or 30 cm).

In the factory a special phantom consisting of 3 parts is used:

- 20 cm body

- 20 cm head

- 30 cm body

The phantom is not delivered with the system.

How to find

• Options > Service > Local Service > Test Tools > Sys. Tests> Band Assessment

How to use

1. Position the phantom so that it lines up with the engraved mark.

The table position is checked.

2. Select the desired modes.

Possible choices: Select all, Deselect all, and Select box

3. Press Go

If results are out of tolerance, go to TSG Image Quality.

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TSG DMS Components 3.2

TSG DMS Power path 0

NOTE Troubleshoot the DMS B power supply in the same way. Theonly difference is that the DMS B consists out of one back-plane, and therefore only one power cable is connected tothe power supply.

The 2 power supplies for the 2 DMS are located behind the metal DMS front covers. Tocheck the power supplies, check the LEDs at the front of the corresponding DMS.

In addition, the supply voltages can be checked as well on the left and right backplane ofDMS A and on the backplane of DMS B.

Tab. 43 TSG DMS power path

NOTE The power cable of DMS B can be used in DMS A for trouble-shooting.

Important: The tolerances given below are valid only for the test points at the backplanes.

Step Action

1 • Check Power LEDs on the DMS power supply. All LEDs must be “on”.

a) If one or more LEDs are “off”-> check input power at DMS power sup-ply. Measure at X1 on the DMS power supply.

b) If all LEDs are “on” -> continue with item 2.

2 • Check LED’s on DMS Backplanes, all must be “on” and green.

a) If voltages are missing at a backplane, the backplane LEDs change fromgreen to red. In this case check the cables between DMS power supplyand the backplanes.

If the cables are o.k. -> DMS power supply or backplane defective.

Test point Ground TACH power supply

10023351

AMS power supply

10023352+24V 24VRET 24 V / 6 A controller 24V

pos_V_D DGND 3.4V / 11A module digital 3.4V

pos_V_A AGND 4.6V / 21A module analog 3.4V

neg_V_A AGND -3.65V / 18A module analog -3.1V

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• To check the voltages at the DMS backplane, evaluate the following test points andLEDs:

Fig. 34: LEDs of DMS backplane

TSG short circuit in power supply

NOTE Troubleshoot the DMS B power supply in the same way. Theonly difference is that the DMS B consists out of one back-plane, and therefore only one power cable is connected tothe power supply.

To track down a short circuit in the power supplies, cables, backplanes, DAS Controller, ormodules, perform the following:

Before following this advice, be sure the mains input for the DMS power supply is ok.

Tab. 44 TSG short circuit in DMS power path

Step Action

1 • Check Power LEDs on DMS power supply.

a) If the LEDs are “off” -> continue with step 2.

2 • Disconnect X30 at left DMS backplane and check DMS power suppy LEDs.

a) If one or more LEDs are “off” -> check input voltage

b) If all LEDs are “on” -> problem is related to left backplane, DAS Control-ler, all modules connected to the backplane.

Disconnect the parts mentioned to isolate the fault

3 • Disconnect X31 at right DMS backplane and check DMS power suppy LEDs.

a) If one or more LEDs are “off” -> check input voltage.

b) If all LEDs are “on” -> problem is related to right backplane, DAS Control-ler, all modules connected to the backplane.

Disconnect the parts mentioned to isolate the fault

4 • If X30 and X31 are disconnected, and the LEDs on the power supply are still“off”, disconnect the 2 power cables (X2 and X3) at the power supply todetermine whether a short circuit is present in the cables.

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TSG UHR mechanics 0

If there are problems with the UHR mechanics, follow the advice provided in the error mes-sage.

To understand the function of the UHR control (implemented in the UMAR), the current

applied to the UHR motor is shown in the next figure.

UHR phi-z comb: Current measurement is not possible. Follow the mechanical checks.

Fig. 35: Current of UHR motor

To identify problems of the UHR control, you may perform the following tests:

Mechanics

• Check whether the mechanics are operating smoothly by moving the UHR in and out byhand. (remove the UHR motor to be able to move the UHR without applying too muchforce)

If the mechanics are not moving smoothly:→Check for parts blocking the UHR.

Service switches

• Using the UHR service mode with the system in standby mode:

- Press “Stop” on the gantry or control box

- Switch on the service switch on the UMAR

- Press S1 (in) and S2 (out) on the UMAR to check UHR comb movement

- Press “Test” on the UMAR to perform a self-test

- Switch off the service switch on the UMAR

• Using the UHR service mode with the system not in standby mode:

- Switch the gantry to “Comp on”

- Switch on the service switch on the UMAR

- Switch the gantry to “Sys on”

- If the ICS aborts with the message “Can’t continue...”, press the “Test” button on theUMAR prior to using S1 (in) or S2 (out)

- Switch off the service switch on the UMAR

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Limit switches

• If the problem is related to the limit switches:

- Check their functionality using the service switch on the UMAR and move the UHR inand out by pressing S1 (UHR in) or S2 (UHR out). (Described above)

Ensure that MOVE LED on the UMAR is activated at both mechanical end stops.

If the LED is not activated at the end stop on one side:Position the UHR in the middle, so that no limit switch is activated.Use a piece of metal, e.g., a screwdriver, to check whether the limit switches areworking properly.

If the LED in the limit switch is not activating:→Check the power supply for the switch on the UHR control→Replace the corresponding limit switch

- For checking the adjustment of limit switches, refer to the document Replacement ofParts: Gantry.

UHR motor

• If the problem is related to the UHR motor:

- Check their functionality using the service switch on the UMAR and move the UHR inand out by pressing S1 (UHR in) or S2 (UHR out). (Described above)

Observe whether the UHR is moving.

If the UHR comb is not moving:Measure the voltage for the UHR motor at UHR control D586 J1 (power) whileactivated via the service switches.→ If the motor is not moving while voltage is present, replace the motor.→ If there is no voltage, replace D586.

Adjustment

• To ensure the UHR is adjusted correctly in the phi-direction, perform an MTF measure-ment.

If the results are in tolerance, the adjustment is OK.

If the results are out of tolerance, perform COMB ALI in the Tune-up platform.

If the comb is fully maladjusted, the core position can be identified by evaluating a meanvalue plot of an UHR mode.

Core position check of UHR comb

If the UHR comb was largely maladjusted or the initial position was lost, you can try andfind the core position by using analyze.

• Start Analyze

Options > Service > Local Service > Test Tools > Analyze

• Select the radio button ICS-Tables

• Mark an UHR mode BaseCal and press Go.

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• The plot of the BaseCal appears.

Fig. 36: Example of an UHR BaseCal plot

• Zoom both edges to see the channel where the UHR comb starts and ends.

Compare your results with this example showing a well-adjusted UHR.The first channel with a higher value is channel 139The last channel with a higher value is channel 534

Disabling the UHR comb

• If a defective UHR comb prevents the system from reaching standby, the comb can bedisabled momentarily.

Fig. 37: Zoom of lower channel side Fig. 38: Zoom of higher channel side

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3. After the next INIT, save the machine configuration by selecting “none” for UHR (referto the example below)

Fig. 40: Factory-specific CT configuration

4. Save a copy of the original license.dat file

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5. Disable the UHR licenses by putting a “#” in front of the related licenses. (Refer to theexample below)

Fig. 41: License.dat Pos. 1 License deactivation

NOTE Do not forget to restore the original configuration once theUHR comb is working again.

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Additional Tests & Hints 3.3

Storage of Test Results 0

• Test results are stored in two different ways:

- As HTML files

Path:c:\Somaris\service\html\report\htmlreport

- As TXT files

Path:C:\Somaris\service\extract

- Additionally, it’s sometimes helpful to use a screenshot to report the result plots:

- Activate the window you intend to capture

- Use Ctr / PrtSc to capture the window

- Start > Programs > Acessories > Paint- Use Edit > paste

- File > save as and use file type gif to reduce the size

Normally, HTML files are used to store test results.

However, the plots of the DMS tests are usually stored in a text file (via Extract to Filebutton). Please note: the file name has to be changed manually. Otherwise, the file willbe overwritten each time the softkey is used.

The file may be displayed using Excel (e.g. after manual remote transfer).

Environmental Conditions 0

Environmental conditions are a possible reason in case of weak ring artifacts.

Check the Somaris log for errors and warnings .

Gantry

Inside the gantry, the temperature is regulated.

To read out the actual values for temperature, use the control platform

The output of the table may be selected in decimal or hexadecimal values.

The gantry has to be in standby mode when accessing the control system.

To read out the actual temperature of the gantry, perform the following:1. Options > Service > Local Service > Control > Table load/modify2. Select Volatile under TABLE SOURCE.3. In the list box TABLE NAMES select T004. Press GoThe parameter set for the table T00 is shown.Use the slider to move to the desired information- gantry temperature [degrees C] The temperature has to be in the range of 26C +/- 4C

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DMS 97


DMS

• Environmental conditions for the DMS are:

- Temperature :

Check the Event log for errors and warnings concerning temperature problems.

Ensure that the DMS is powered on over night.

If raw data is available for the images the customer is complaining about, useAnalyze to read out the temperature from the header data.This indicates the temperature at the time of data acquisition.

Overview -Temperature switches

• Temp. Switch at right DMS A backplane:

- Opens at 38C +/- 2%

- Closes at 27C +/- 2%

• Temp. Switch at DMS B backplane:

- Opens at 38C +/- 2%

- Closes at 27C +/- 2%

Hints for defective channel detection 0

The following 3 types of defective channel tables are available at the system

• CheckUp tables

- Generated automatically at every check-up.- An empty table is available for every check-up (temporary table).

- Defects found during checkup will be stored in the check-up table. With the nextcheckup, this table will be empty again.

• TuneUp tables

- Generated during automatic detection with the service function.

- The entries are updated with the next detection under service

- Only the tune-up tables may be edited manually (in case of sporadic problems).

- Manually entered defects will remain permanently in the tune-up table and can onlybe removed manually. They have to be removed after module replacement.

• IRS tables

- At checkup, the tables are derived by merging the check-up and tune-up tables.

- During detection under tune-up, the irs table is derived only from table tune-up

- The tables are located on the ICS and are transferred at every check-up to the IRS.

- The information about the defects in the IRS table is derived as follows:

- for 32 x 600: all information is copied from the tune-up tables.

- for 24 x 1200: all information is copied from the tune-up tables.

- for all other slice combinations the information is derived from these tables

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Additional information for defective channel detection

• After part replacement (e.g. module) or if you do not succeed removing unsatisfactorychannels, delete the IRS tables in ICS as follows:

1. Go to C:\Somaris\service\datastore\icstable

2. Delete all files starting with badchannelsxxxxx

3. Start an automatic detection under service to create an actual channel status.

A partial tune-up as described in the guided tours follows.

Viewing the detector statistics

Select Detector Statistics

The number of defective elements are shown for the various collimations (tune-upand checkup).

Using Reports to view details of the Defective Channels Correction

1. Open an additional window and choose Reports .

2. From the menu bar TuneUp/QA/Tests choose:

TuneUp > Table Generation > Def. Channels

3. Double-click Report to view the results.

Detector Statistics shows all currently defective channels.Table Editing History shows the history of the detection.- Added by Automatic Detection and- Manually Added/Removed

Table Conditions shows all affected slice combinations within the IRS table.Affected Modules shows the slot as well as necessary replacements (change =has to be replaced).Comments shows additional information, in case a comment was added by thecustomer service engineer.

Adding a comment

1. Use the slider to move down to Comments

2. You can now enter a comment for a manually patched channel.

Generally used to document details in case of sporadic problems.

Separate between module and other components 0

If one ore more broken channels have been found using the guided tour or other tests, youhave to find out if the problem is really caused by the module or by other components.

1. Cross module cable on DMS backplane with the neigboring one.

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DMS 99


2. Close the DMS covers and repeat the test or mode that showed errors before.

If the error moves to the neighboring slot, the module or module cable is broken.Continue with step 3.

If error does not move, the corresponding backplane (or DAS Controller) is defec-

tive.

NOTE A second peak may appear now in the displayed plot. This isnormal with crossed/swapped module cables, if no new cali-bration,(e.g. a new Checkup or Setup/Calibration) has beenperformed prior to starting the second test run.

3. To distinguish between the module and module cable, swap the whole module cable (not crossed) with the cable of the neighboring module. Close the DMS covers andrepeat the test or mode that showed errors before.

If the error moves to the neighboring slot, the module cable is defective.

If error does not move, the module is defective.

4. Swap module cable to its original position.

5. Run assignment test to check the addressing of the DAS Controller.

If the assignment test fails, replace the DAS Controller.

Replace corresponding backplane.

How to interpret the physicist’s line 0

To find the decoding for the physicist’s line, go to: - Somaris > Help > Contents and Index and

- select the tabcard Search and

- type in physicist’s line

The explanation is shown

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Datalink 101


2. Yellow Signal: “off” if no signal or signal with low amplitude detected.

3. Orange Sync: “off” or reduced intensity if sync error detected.

LEDs on G-Recs in IRS

1. Red NoSignal: “on” if no optical signal or signal with low amplitude is detected.

2. Red Error: “on” if unsatisfactory readings are detected. When a segment on the dataring is defective, the LED blinks synchronous to gantry rotation, depending on the angu-lar position of the defect.

3. Red 8-Bit error counter Err7...0: counts unsatisfactory readings received from DCON.

Abbreviations

Tx -> Transmitter Electronics

Rx -> Receiver Electronics

DCON -> DAS Controller

G-Rec -> Receiver in IRSFODL1...3 -> Fiber optic data link (connections for fiber optic cables at DCON)

General: Receivers with Revision <B 0

If any transmission errors occur, check all receivers (one rotating, 3 stationary):

If they have a revision level smaller than “B”, they may have too long pins at the connector.Either replace them by Rev. B receivers or shorten the pins as follows:

Cut the pins on the receiver board with side cutters. The pins must be 1mm long after theyare cut.

Fig. 42: Example: Rotating receiver board Pos. 1 Pins to be shortened to 1 mm

Prerequisites 0

For a quick check of the data path, a spare fiber optic cable and a fiber optic couplerare required. A short and long fiber optic cable are delivered with every system. Usethese fiber optic cables to patch a certain segment of the data path in order to isolate theproblem.

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NOTE At the Tx and Rx modules, simplex fiber optic connectionsare used. Components connected to UMAR/UMAS useduplex connections.

The delivered spare fiber optic cables are duplex connec-tions. To use these cables for simplex connections, separatethe cables at the connector.

The image below shows one of the delivered spare fiber optic cables with its connectorsseparated for simplex use..

Fig. 43: Spare fiber optic cable with coupler Pos. 1 spare fiber optic cable

Pos. 2 coupler

Pos. 3 fiber optic connectors, separated for simplex connections

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TSG Datalink 4.1

Depending on the kind of error, select the corresponding section. Follow the steps in thetable and use the figures to verify the connections.

TSG permanent errors on DAS Controller/s -> IRS Receiver/s 0

Fig. 44: DMS Data Paths

Tab. 45 TSG permanent errors DCON to IRS

Step Action

1 • Check power at the double Tx module.

a) if the green LED is “off”, -> Tx is module defective or power from PDR ismissing. Check power supply.

Additionally, perform the Data Link Test and check gantry error monitorfor errors reported from UMAR: Power error

b) If the LED is “on”, continue with step 2.

2 • Check signal at the double Tx module.

a) If one or both of the yellow LEDs are “off”, -> missing optical signal fromDCON/s or broken/dirty fiber optic cable connections, or Tx moduledefective. Clean the fiber optic cable and check again. If LED is still “off”,continue wih step 3.

Additionally, perform the Data Link Test and check gantry error monitorfor errors reported from UMAR: Signal error


c) if the orange Sync LED is on, but with reduced brightness -> check qual-

ity of signal. Refer to (TSG data quality at Tx module / p. 105)

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3 • Check output of DCON by establishing a direct connection between DCONand G-Rec with the spare fiber optic cable.

a) If Red NO Signal LED on G-Rec is “on” -> DCON defective.b) if Red NO Signal LED on G-Rec turns “off” -> DCON and G-Rec o.k.

Establish the origin connection and swap the two fiber optic cables at theTx input. If yellow LED on Tx module is “on” now, -> cable betweenDCON and Tx module defective. If yellow LED is still “off” -> replacethe Tx module.

4 • Check power at the corresponding stationary Rx module (A or B).

a) if the green LED is “off” -> Rx module defective or power from UMAS ismissing. Troubleshoot the power path first.

b) if the LED is “on”, continue with step 5.

5 • Check signal at the Rx module.

a) if the yellow LED is “off”, -> missing signal from Transmitter, or rotatingdata ring defective, or receiver carrier maladjusted/defective, or Rx mod-ule defective. Continue with step 6.

b) If the yellow LED is on, continue with step 7.

c) if the orange sync lock LED is on, but with reduced brightness -> checkquality of signal. Refer to (TSG data quality at RX modules / p. 106)

6 • Check the data ring.

a) Swap the two Rx modules (Rx A and Rx B). If the error moves -> replacethe Rx module.

b) if error still at initial position, adjust the triple receiver carrier (refer toreplacement of parts section) and check the microstrip antenna. Refer to(How to check the transmitting antenna / p. 118). If resistance of micros-trip antenna is o.k -> replace the Tx module.

If resistance of microstrip antenna is not ok -> replace the RotatingData Ring.

Call HSC before replacing the Data Ring.

7 • Check the connection Rx module to G-Rec.

a) If red No Signal LED at G-Rec is “on” -> missing signal from Rx module,or broken/dirty fiber optic connection, or G-Rec defective. Clean the fiberoptic cable and check again. If LED is still “on”, continue with step 8.

b) If the LED is “off” now, run the datalink test (Data Link Test / p. 114).

Step Action

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Datalink 105


TSG data quality at Tx module 0

The orange Sync LEDs (one for each DMS) must show a noticeable increase in light inten-

sity in a idle system, or when plugging and unplugging the fiber optic cable. Before startingtroubleshooting for data quality, perform the TSG for permanent errors first.

Tab. 46 TSG data quality at TX modules

8 • Use spare cable between Rx module and G-Rec.

a) If red No Signal LED at G-Rec is still “on” -> Rx module or G-Rec in IRS

defective. Continue with step 9.b) If the No Signal LED is “off” now -> replace the fiber optic cable.

9 • Swap the two fiber optic cables at Rx modules or at the G-Recs in IRS.

a) If errors move to the other G-Rec -> replace the Rx module.

b) If error still at first G-Rec-> replace the G-Rec.

Step Action

Step Action

1 • Unplug and plug the fiber optic cables at the double Tx module.

a) if one Sync LED shows reduced intenisty (e.g. due to blinking at a highrate) -> DCON output broken, or broken/dirty fiber optic connection fromcorresponding DCON, or double Tx module broken. Clean the fiber opticcable and check again. If LED still shows reduced intensity, continue with

step 2.

b) If both Sync LEDs show reduced intensity (e.g. due to blinking at a highrate) -> DCON output broken, or the Tx module is defective. Continuewith step 3.

2 • Check the DCON by swapping fiber optic cables at TX module.

a) Swap the fiber optic cables at the TX module. If the error moves (otherLEDshows reduced intensity now) -> DCON or fiber optical cabledefective. Continue with step 3.

b) if the error does not move, establish the original configuration and con-tinue with step 3.

3 • Check the DCON output using a spare fiber optic cable.

a) Connect FODL1 to the corresponding Tx input with the spare cable. If theorange LED is o.k. now -> replace the fiber optic cable.

b) If the orange LED still shows reduced light intensity (with spare cableinstalled), -> DCON or Tx module defective. Continue with step 4.

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TSG data quality at RX modules 0

First ensure that the quality of the data signal at the Tx module is OK (see above). Whenplugging the fiber optic cable into the Tx module, there must be a noticeable increase inlight intensity at the orange Sync LED on both, the Tx and Rx modules, in an idle system.

Tab. 47 TSG

4 • Check the DCON using the indicator on rotating fastlink transmitter.

a) Connect FODL1 to the rotating Tx module for fastlink data using the

spare fiber optic cable. If the Sync LED at the rotating fastlink transmitteralso shows reduced intensity -> replace DCON.

b) If Sync Lock LED on rotating fastlink transmitter shows a noticeableincrease in light intensity-> replace the Tx module.

5 • Additionally, run Data Link test.

a) Check gantry error monitor in Data Link test for errors reported byUMAR: Link error. ->replace the Tx module.

Step Action

Step Action

1 • Unplug and Plug the fiber optic cables at the Tx module.

a) if the Sync LED at one Rx module permanently shows reduced intensity(e.g. due to blinking at a high rate) -> Tx module (output) defective, or

Rotating Data Ring defective, or receiver carrier maladjusted/defective,or Rx module defective. Continue with step 2.

b) if both Sync LEDs show reduced intenisty (e.g. due to blinking at a highrate) -> Tx module defective.

2 • Check the Rx module/s.

a) Swap the 2 Rx modules (Data Path A and B) and check the Sync LEDs.If the error moves to the other Data Path, -> replace the Rx module.

b) If the error did not move, swap back the modules and continue with step3.

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Datalink 107


TSG sporadic errors in link DCON -> IRS 0

The following table describes step by step how to troubleshoot sporadic transmission prob-lems.

Tab. 48 TSG

3 • Adjust the receiver carrier (refer to replacement of parts section) and checkthe microstrip antenna. Refer to (How to check the transmittingantenna / p. 118)

a) If resistance of microstrip antenna is o.k., replace the following parts inthe order shown -> 1. Tx module, 2. Receiver carrier, 3. Rotating dataring.

b) If resistance of microstrip antenna is not o.k. -> replace the RotatingData Ring.


4 • Additionally, run Data Link test.

a) Check gantry error monitor in Data Link test for errors reported by UMAS:Link error.

b) check for angle dependent error distribution. If error angle dependent -> replace the rotating data ring.


Step Action

Step Action

1 • Check indicators for sporadic errors:

a) Check for IRS warnings in the Event Log

b) Check error LED counter on GRecs

For detailed instructions, Refer to (Step 1 (checking) / p. 108)

2 • Debug for random transmission errors:

a) Check the data ring and the fiber optic cables using the spare fiber opticcable.

b) Swap the data ring channels

For detailed instructions, Refer to (Step 2 (debugging) / p. 108)

3 • Localize the source of error:

a) Check for errors occurring in the DMS or IRS

b) Check for errors occurring at about the same gantry angle

c) Search for external interference as source of error

d) Search for dominant source of errors

For detailed instructions, Refer to (Step 3 (localizing) / p. 109)

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Step 1 (checking) 0

• Check indicators for sporadic errors

a) Check for IRS warnings in the Event Log:

The IRS SW counts the data errors encountered in a scan and generates a warningmessage. Check the logbook for IRS errors, only the CRC errors are significant for datatransmission. Other types of errors detected by IRS, e.g. HV_DROP, are not related todata transmission.

b) Check Error LED counter on G-Recs:

The error counter at the G-Rec input electronics counts the CRC and synchronizationerrors for the duration of the scan, i.e. not only during radiation but also during the biasphase and during pauses between sequential scans. This error counter is displayed inbinary code with an 8-bit red LED bar on GRec. This counter is only active during thescan with data transfer and after mode load until the scan ends. Check that the greenData LED on G-Rec is “on”, when investigating for random data transmission errors. To

use this counter as a random error detector, it is necessary to load a scan (load themode) and to perform investigations before or during the scan.

Step 2 (debugging) 0

• Debug for random transmission errors

a) check the data ring and the fiber optic cables using the spare fiber optic cable

- Disable gantry rotation

- Use the spare fiber optic cable to connect the DCON outputs directly to the G-Recinput.

- Perform exactly the same (static) scan that is subject to random errors with a normalconfiguration. If the random error continues to persists, the problem is within DCONor IRS. Otherwise, the debug procedure has to be refined.

The fiber optic cables between DCON → slip ring or between slip ring → IRS may bepartially broken or have dirty ferrules in the connectors. Especially in the gantry, theconnectors may be contaminated by carbon dust from the slip ring brushes. In thiscase, the signal at the fiber optic cable output is lower than usual. However, the sig-nal detect indicators may not trigger although the signal quality is poor. To isolate theproblem, measure the fiber optic cable loss factors as described in the appendix andreplace the fiber optic cable in case of higher losses. Alternatively, use the spare fiberoptic cable to successively patch the fiber optic cable in question. If you get betterresults (reduced number of transitory errors or no error at all), clean the ferrules orreplace the fiber.

b) swap the data ring channels

The data path for DMS A uses identical parts as the DMS B data path. For debugging,the A components can be swapped with the B components. For troubleshooting, the Adata can be sent via the B path.

Swap the fiber optic cables at the double Tx module and at the G-Recs to use theother path.

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Step 3 (localizing) 0

• Localize the source of error

The Data Link Test automatically performs a statistical analysis regarding error distribu-tion. Different histograms can be displayed.

a) Check for errors occurring in the DMS or IRS

In case of a defective DCON or G-Rec, the data errors are apparently random andapparently due to transmission. However, in reality the error occurs before transmis-sion in the DCON and after the transmission in the G-Rec. Select Bit Errors in the DataLink Test (Data Link Test / p. 114) to get a histogram plot of the bit error position withinthe 16-bit data word. If the errors always occur at the same bit position(s) within the16-bit word, when repeating the data link test:

DCON or G-Rec defective, transmission across the Data Rings o.k.

Example for Bit Error histogram:

Fig. 45: Error bit position histogram

b) Check for errors occurring at about the same gantry angle:

Problems with the mechanical alignment of slip ring antennas can produce randomerrors. Select both, Data Words Error and CRC Errors in the Data Link Test to displaya histogram plot of error distribution around the rotation. The Data Words Error analy-

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110 Datalink



sis may be slower but it checks for every bit error. The CRC Errors analysis checksonly for block errors and is faster. The example below shows errors concentrated at thesame angular positions of the data ring.

Rotate the gantry by hand to this angular position and check the structure for

defects and mechanical alignments. (0

o

is X-ray tube A at 3 o’clock).Example for relation between errors and rotation angle histogram:

Fig. 46: Histogram of error versus rotation angle

c) Search for external interference as source of error:

Random errors in the data path may be caused by the following external factors:

- Noise generated by the frequency converter for rotation

- Noise generated by the HV Generator

- Mechanical assymetries in the antenna system

- External equipment (e.g. therapy equipment, ovens,...)

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Datalink 111


Select both the Error Bursts and Error Free Intervals in the Data Link Test to obtaintwo histograms that plot the error distribution within the data stream (distribution of theerror burst length - EBL and error free interval - EFI).

The following 3 cases show typical histograms for different error sources:

Case 1In this case both histograms have a Gauss (bell) shape. This suggests a periodic per-turbation source such as the frequency inverter for gantry rotation or other power sup-ply noise.

Check the high-power connections at the generator, the grounding connection,and the high power carbon brushes.

Perform tests with the rotation driver disabled or without radiation to better iden-tify the perturbation source.

Fig. 47: Burst and EFI histogram case 1

Case 2

In this case only the burst histograms have a Gauss (bell) shape, whereas the EFI his-togram decreases linearly. This suggests a non-periodic perturbation source such asexternal equipment operated in the vicinity of the CT examination room and generatingpower line interference.

Check the quality of the hospital AC power lines (line transient spike analyzer)and the grounding of the CT system as well as other hospital equipment operat-ing in the vicinity.


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112 Datalink



Case 3

In case bursts histograms are concentrated and occur at very short burst lengths,whereas the EFI histogram decreases linearly, this is suggestive of a poor sig-nal-to-noise ratio at some fiber optic input or at the RF input for the Rx module.

Check the fiber optic cables, clean the connectors, and align the receiver carrier.


d) search for dominant sources of error:

Each error source may contribute to the error budget, but only one is usually dominant.The Data Link Test is a useful tool for locating the dominant source for errors. The RFlink across the data slip ring is subject to electromagnetic interference produced withinthe gantry. Major sources for this interference are the ring motor and its frequencyinverter as well as the high-voltage generator and power supplies on the rotating gan-try. In order to identify the dominant source for errors, the debug strategy eliminatesone or more potential sources and investigates the way they influence error statistics.Accordingly, the data link test provides predefined test modes that deal with this debugstrategy. For example, to investigate the contribution of the X-ray generator to the errorbudget, perform the data link test using scans without radiation.

Investigate the initial error statistics:

To get an idea about the initial error profile, perform the data link test with patient-likemodes, i.e. modes that simulate a real scan. Use either topogram-like modes ("Static 0deg, X-Ray" "Static 90 deg, X-Ray") or sequence-like modes ("Rot 0.33s, X-Ray"... "Rot1.000s, X-Ray").

Try to identify if the errors are related to particular parameters such as rotationspeed, tube angle, etc...

Investigate the contribution of the rotation driver:

To investigate the contribution of the rotation driver to the error budget, perform thedata link test with the predefined modes "Static X-Ray1" and "Static X-Ray2". Thesemodes fully disable rotation, including active braking. The frequency inverter is dis-abled via SW and thus generates no interference at all. This is not equivalent to switch-ing the rotation switch OFF! These tests may be performed only in the static mode. Thegantry should be positioned either via the service platform or by hand at various angu-lar tube positions or at positions where previous tests showed an increased error proba-

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Datalink 113


bility. If the error statistics change significantly as compared to previous tests, thedominant source for errors is the rotation driver and investigations should be pursued inthis direction.

Investigate the contribution of the X-ray generator:

To investigate the contribution of the X-ray generator to the error budget, perform thedata link test with the predefined modes "Rot 0.33s" ... "Rot 1.000s". These modes dis-able X-ray generation for various rotation speeds. Use the rotation speeds that previ-ously showed increased error probability. If the error statistics change significantly ascompared to previous tests, the dominant source for errors is the X-ray generator andinvestigations should be pursued in this direction.

Fine tuned investigation:

After having used the above steps, it may become obvious that other test mode(s) maybe more suitable for checking out a particular situation. In this case, edit theuser-defined test modes "Static20.dat" and "Rot20.dat" with or without X-ray to fit theparticular debug needs.

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Tests for data transmission 4.2

Cleaning a fiber optic cable 0

The cable's performance may degrade because of dust or dirt covering the input core inthe cable’s receptacle.

Fig. 50: Cleaning optical connectors

Data Link Test 0

Scope

• The data link test is a sequence of scans performed automatically with the DMS config-ured to generate test data (assignment mode). The data received are automaticallyanalyzed in the IRS/ICS for every incorrect bit. Error statistics are generated that allowfor locating sources for error. If this test is successful, the transmission DMS to IRS isworking well.

• The data link test may be performed at different rotation speeds or without rotation(ROT or STATIC modes) in the static mode with or without active braking of the gantryvia the rotation driver, with radiation at different levels of X-ray power or without X-ray.

How to find

• Options > Service > Local Service > Test Tools > Sys.Communication > Data Link

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Datalink 115


Fig. 51: Data link test

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116 Datalink



How to use

• Perform the data link test after a careful analysis of IRS logbook errors. Search forthose modes (rotation speed, X-ray power level, gantry tilt, etc...) that are most prone totransmission errors and test the data link with these particular modes.

a) Press Select all, or select single modes, depending on the error pattern (e.g. rot.speed, X-ray, etc....)

b) Press Go

c) Wait for the Press START key to appear and then press the Start button

If CRC errors or data errors are detected during the measurement, histogramevaluations can be selected. The evaluations are only available in case errorsare detected (see next screenshot). For detailed informations regarding the his-togram evaluations, refer to (TSG sporadic errors in link DCON -> IRS / p. 107).

Fig. 52: Data link test, possible histogram evaluations

• The analysis SW will increment an error counter for each CRC error. The total numberof transmission errors is available and displayed as test result. The error counter runsover all readings into the scan that include at least five complete rotations in order tofind the relationship between tube angle and error occurrence. In the case of an errorcounter that is not zero, its time evolution can be plotted for all scans together with thetube angle position as depicted below:

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Datalink 117


Fig. 53: Example of tube angle and error count versus frames

The X axis of the plot is the reading number. The vertical axis of Channel 2 (green plot) isthe number of errors. The vertical axis of Channel 1 (yellow plot) is the angular tube position

(0...360oC) as explained below.

Selectively check or uncheck the channel 1,2 checkboxes to change the vertical scale.

The gantry error monitor

The power, signal, and link errors reported by the Tx and Rx electronic modules in the slipring are monitored dynamically during the scan via the UMAR on the rotating gantry andvia the UMAS on the stationary gantry. These errors are the same debug signals that areindicated by the green, yellow and orange LEDs available on both Rx and Tx modules. BothUMAR and UMAS HW count the number of times these errors were activated during thescan (error counter) as well as how long the errors were active during the scan (error time).This feature is useful for identifying transitory errors that occur due to loose contactscaused by mechanical vibrations during rotation that are otherwise not detectable.

Gantry angle(deg)

0 30 60 90 120 150 180 210 240 270

Tube A posi-tion (x o’clock)from the front

3 4 5 6 7 8 9 10 11 12

Tube A posi-tion from thefront

East(right)

South(bot-tom)

West(left)

North(up)

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Appendix 4.3

How to check the transmitting antenna 0

The structures of the data rings can be measured with a digital multimeter. The figure belowshows how to measure the innermost rotating data ring. The structures can be measuredat the termination (see image below), and next to the transmitter 180 degrees shifted (sametest points at opposite site of data ring). The results may be slightly different ~1 Ohm

1. Use a digital multimeter to measure the resistance at the following test points:

Fig. 54: Test points for rotating data rings

Measure between Nominal value

TP1 and TP3 79 Ohm +/- 1 OhmTP2 and TP4 79 Ohm +/- 1 Ohm

TP1 and Ground 39.5 Ohm +/- 0.5 Ohm




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Datalink 119


NOTE Measuring the resistance is important to find an interrupt orshort circuit in the structure. The nominal values shouldserve as a guideline. If the measured values are out of toler-ance, call HSC before replacing the data ring.

Measuring the fiber optic signal along the link 0

The fiber optic cable power at both outputs of DCON and at the fiber optic output of the slipring Rx module have to be high enough for reliable data transmission. The fiber opticreceivers in the UMAR, slip ring Tx, and G-REC have built-in signal level detectors thatreport an error when the signal falls below a safe minimum level. However, for error identi-fication it is important to know if the problem is the incoming signal or the receiving partitself. It may be possible that the power delivered via fiber optic cable to the input is highenough, however, the fiber optic receptacle in the receiver module is covered with dust ordirt, and the incoming light does not reach the destination. The fiber optic signal can bemeasured at any point in the link using an optical power meter (e.g. the HP 8410A or HP8153A). The power level of the fiber optic cable should be at least -9 dBm avg. at 850 nminto a 62.5/125 MMF fiber optic cable.

The modulation signal (fiber optic cable extension ratio) can be optimally measured with anoscilloscope and a fiber optic probe, e.g. Tektronix 6701B. The signal amplitude is typically400µW.

Note: A fiber optical cable mounted in the gantry is difficult to measure with the aboveinstruments unless the cable is fully released from the gantry cable tree. To avoid this oper-ation, you may use the spare fiber optical cable and the adapter to extend a cable end up

to the measuring instrument. Consider additional loss in the spare cable to correct the finalresult.

Check the electrical RF signals at the Rx modules 0

The Rx modules receive RF signals via the capacitive coupling between the transmittingrotating slip antenna and the stationary receiving segment antenna. The RF coupling con-dition depends on the mechanical tolerances. The tests below have to be performed bymanually rotating the gantry 360 degrees.

Rotate the gantry by hand, check status of the LEDs at the Tx and Rx modules. Proceed

as described below.Reasons why Signal detect LED on Rx module is off:

• Tx module defective (output)

• Slip ring antenna system is defective or needs alignment

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5- 5Fastlink

General 0

Safety 0





NOTE Follow C-MOS guidelines when handling data transmissionparts.

Notes 0

This chapter contains information on how to troubleshoot the fastlink connections and thefastlink paths.

NOTE All fastlink ports at the UMAR/UMAS and at the correspond-ing connected components are compatible. By using a patch

cable, every port can be connected to any other port, tocheck transmit and receive functions.

Every fastlink port has at least 2 LEDs that indicate thereceive status. It is important always to check the LEDs atboth components to determine if the problem is related to atransmit problem of the first component, or a receive problemof the other component.

The following troubleshooting guides (TSG’s) are covered in this chapter:

1. Direct fastlink connections in rotating part of gantry

All rotating components connected to the fastlink are connected via the UMAR2. Direct fastlink connections in stationary part of the gantry

All stationary components connected to the fastlink are connected via the UMAS

3. Transmission Path UMAS to UMAR

Data transmission between UMAS and UMAR is achieved via the stationary transmitter,the stationary data ring, and the rotating receiver assembly.

4. Transmission Path UMAR to UMAS

Data transmission between UMAR and UMAS is achieved via the rotating transmitter, therotating data ring, and the stationary receiver assembly.

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122 Fastlink




Tx module-> Transmitter electronics module

Rx module -> Receiver electronics module

General: Receivers with Revision <B 0

If any transmission errors occur, check all receivers (one rotating, 3 stationary):

If they have a revision level smaller than “B”, they may have too long pins at the connector.Either replace them by Rev. B receivers or shorten the pins as follows:

Cut the pins on the receiver board with side cutters. The pins must be 1mm long after theyare cut.

Fig. 55: Example: Rotating receiver board Pos. 1 Pins to be shortened to 1 mm

Prerequisites 0

For a quick check of the data path, a spare fiber optic cable and a fiber optic couplerare required. A short and long fiber optic cable are delivered with every system. Usethese fiber optic cables to patch a certain segment of the data path in order to isolate theproblem.

NOTE At the Tx and Rx modules, simplex fiber optic connectionsare used. Components to and from UMAR/UMAS use duplexconnections.

The delivered spare fiber optic cables are duplex connec-tions. To use these cables for simplex connections, separatethe cables at the connector.

The image below shows one of the delivered spare fiber optic cables with its connectorsseparated for simplex use.

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Fastlink 123


Fig. 56: Spare fiber optic cable with coupler Pos. 1 spare fiber optic cable

Pos. 2 couplerPos. 3 fiber optic connectors, separated for simplex connections

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124 Fastlink



TSG Fastlink 5.1

Depending on the error message, select the corresponding TSG. Follow the steps in thetable and use the figures to verify the connections and LED states.

TSG rotating fastlink connections 0

The following figure shows the rotating fastlink connections and the LEDs which are usefulerror indicators.

Fig. 57: Rotating fastlink connections

LEDs on UMAR

1. NoSD: “On” if no optical signal, or signal with low amplitude is detected

2. Error: “On” , if Sync or CRC error detected

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Fastlink 125


LEDs on XDC A and XDC B

1. NO SIG: “On” if no optical signal, or signal with low amplitude is detected

2. Error: “On” if Sync or CRC error detected

LEDs on Tube collimator A and Tube collimator B

1. FL Sig: “On” if no optical signal, or signal with low amplitude is detected

2. FL Err: “On” if Sync or CRC error detected

LEDs on left backplane DMS A and backplane DMS B

1. COM_BUS: “Green” if a valid fastlink protocol is received.

“Red” if fastlink protocol is not valid.

Tab. 49 TSG rotating fastlink connections

TSG stationary fastlink connections 0

The following figure shows the stationary fastlink connections and the LEDs which are use-ful error indicators.

Step Action

1 • Check the red NoSD and Error LED at the UMAR and at the connected com-ponent (e.g. tube collimator, XDC).

a) If one or both LEDs (Error and NoSD) are “on” or blinking at UMARor/and at the connected component -> clean the fiber optic cable (Clean-ing a fiber optic cable / p. 134). If LEDs are still “on”, continue with step 2.

2 • Switch “off” and “on” the gantry at the control box.

a) If LEDs are still “on” or blinking, continue with step 3.

3 • Check the UMAR by swapping connectors.

a) Swap the fastlink connector at the UMAR with the neighboring one (e.g.

swap the A-component with the B-component). If the error moves to theneighboring slot, -> UMAR o.k., fiber optic cable or the connected com-ponent defective. Swap the connectors to their original positions andcontinue with step 4.

b) If the error does not move to the other slot, -> UMAR defective.

4 • Check the connection using a spare fiber optic cable.

a) Connect the corresponding slot of the UMAR to the connected compo-nent with the spare fiber optic cable. If LEDs are still “on” -> replace theconnected component.

Before replacing the component, connect the component to any other

fastlink port with the spare fiber optic cable, and check the LEDs to verifythe defect.

b) if LEDs are “off” now -> cable between UMAR and component defec-tive.

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126 Fastlink



Fig. 58: Stationary fastlink connections

LEDs on UMAS

1. NoSD: “On” if no optical signal, or signal with low amplitude is detected


LEDs on XGS A and XGS B in PDC (D703)

1. Light Err: “On” if no optical signal, or signal with low amplitude is detected

2. Link Err: “On” , if Sync or CRC error detected

LEDs on PHS (LMAS)

1. Transceiver Signal detect: “On” if no optical signal, or signal with low amplitude isdetected

2. Receive Error: “On” , if Sync or CRC error detected

LEDs on IRS

1. FL NOT READY: not used

2. FL NO SIGN: “On” if no optical signal, or signal with low amplitude is detected

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128 Fastlink



Fig. 59: Fastlink path from UMAS to UMAR

LEDs on stationary Tx module:

1. Power: “Off” if power to the Tx module is missing.

2. Signal: “Off” if no signal, or signal with low amplitude is detected

3. Sync: “Off or reduced intensity (blinking)” if Sync or CRC error detected

LEDs on rotating Rx module:



3. Sync: “Off or reduced intensity” if Sync or CRC error detected.

LEDs on UMAR

1. NoSD: “On” if no signal, or signal with low amplitude is detected


Tab. 51 TSG fastlink path UMAS to UMAR

Step Action

1 • Check all fastlink indicators (LEDs) in the path UMAS->UMAR.

a) if one or more LEDs in the path are not in idle state, continue with step 3.

b) if all LEDs are idle, continue with step 2.

2 • Check output of UMAS by establishing a direct connection between UMASand UMAR with a spare fiber optic cable.

a) If Red NoSD and Error LED at UMAR are “on” -> UMAS defective.

Before replacing the UMAS, connect UMAS to any other fastlink port with

the spare fiber optic cable, and check the LEDs to verify the defect.b) if Red NoSD and Error LED at UMAR are “off” -> UMAS and UMAR o.k.

Establish the original connection and continue with step 3.

3 • Check power at the stationary Tx module.

a) If the green LED is “off”, -> Tx module defective or power from UMAS ismissing. Check the power path.


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Fastlink 129


4 • Check signal at the TX module.

a) If the yellow LED is “off”, -> missing signal from UMAS or broken/dirty

fiber optic cable connection, or TX module defective. Clean the fiber opticcable (Cleaning a fiber optic cable / p. 134). If yellow LED is still “off”, ->connect the UMAS and Tx module with the spare fiber optic cable. If theproblem is not related to the cable, establish the original connection andcontinue with step 5.

b) if the orange Sync LED is “on”, but with reduced brightness -> checkquality of signal (TSG data quality at Tx modules / p. 132).

c) If all LEDs are “on”, continue with step 6.

5 • Swap the Tx module.

a) Swap the Tx module with the rotating one. If the error moved-> replace

the Tx module.

6 • Check power at the Rx module.

a) If the green LED is “off”, -> Rx module defective or power from UMAR ismissing. Troubleshoot the power path first.



a) if the yellow LED is off,-> missing signal from Transmitter, or stationarydata ring defective, or rotating receiver carrier defective. Continue withstep 8.

b) if the orange sync lock LED is “on”, but with reduced brightness -> checkquality of signal. (TSG data quality at Rx modules / p. 133)


8 • Check the stationary data ring

a) Measure the resistance of the stationary data ring (How to check thetransmitting antenna / p. 135). If resistance not o.k., replace the dataring.

Call HSC before replacing the data ring.

b) Adjust the rotating receiver carrier. If the error still persists, continue with

step 9.

9 • Check the connection from Rx to UMAR.

a) If the red LEDs at the UMAR are “on” -> missing signal from Rx module,or broken/dirty fiber optic connection, or UMAR defective. Clean the fiberoptic cable (Cleaning a fiber optic cable / p. 134). If LEDs are still “on”,establish the original connection and continue with step 10.

Step Action

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130 Fastlink



TSG for connection UMAR -> UMAS 0

The following figure shows the fastlink path from the UMAS to the UMAR, and the LEDs

which are useful error indicators.

NOTE The UMAR->UMAS path uses the outermost structure of therotating data ring. To isolate the data ring, the middle or innerstructure (DMS A/B path) can be used temporarilly. Use theTx module and Rx module of the DMS data path, and tempo-rarily establish fastlink connections to check the data ring(use the spare fiber optic cables).

Fig. 60: Fastlink path from UMAR to UMAS

LEDs on rotating Tx module:



3. Sync: “Off or reduced intensity (blinking)” if Sync or CRC error detected

LEDs on stationary Rx module:



3. Sync: “Off or reduced intensity” if Sync or CRC error detected.

LEDs on UMAS

1. NoSD: “On” if no signal, or signal with low amplitude is detected

10 • Use the spare fiber optic cable between Rx module and UMAR.

a) If red LEDs at UMAR are still “on” -> Rx module or UMAR defective. Con-

tinue with step 11.b) If the Error LED is “off” now -> Replace the fiber optic cable.

11 • Swap the Rx module with another one and check the LEDs at the Rx moduleand UMAR.

a) If LEDs at UMAR are still “on”-> replace the UMAR.

Step Action

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Fastlink 131



Tab. 52 TSG fastlink path from UMAR to UMAS

Step Action

1 • Check all fastlink indicators (LEDs) in the path UMAR->UMAS

a) if one or more LEDs in the path are not in idle state, continue with step 3.

b) If all LEDs are idle, continue with step 2.

2 • Check output of UMAR by establishing a direct connection between UMARand UMAS with a spare fiber optic cable.

a) If Red NoSD and Error LED at UMAS are “on” -> UMAR defective.

Before replacing the UMAR, connect UMAR to any other fastlink portwith the spare fiber optic cable and check the LEDs to verify the defect.

b) if Red NoSD and Error LED at UMAS are “off” -> UMAS and UMAR o.k.

Establish the original connection and continue with step 3.

3 • Check power at the rotating Tx module.

a) If the green LED is “off”, -> Tx module defective or power from UMAR ismissing. Check the power path.


4 • Check signal at the Tx module.

a) If the yellow LED is “off”, -> missing signal from UMAR, or broken/dirtyfiber optic cable connection, or Tx module defective. Clean the fiber opticcable (Cleaning a fiber optic cable / p. 134). If yellow LED is still “off”,

connect the UMAR and the Tx module with the spare fiber optic cable. Ifthe problem is not related to the cable, establish the original connectionand continue with step 5.

b) if the orange Sync LED is on, but with reduced brightness -> check qual-ity of signal. (TSG data quality at Tx modules / p. 132)


5 • Swap the Tx module.

a) Swap the Tx module with the stationary one. If the error moved->replace the Tx module.

6 • Check power at the Rx module.

a) If the green LED is “off” -> Rx module defective or power from UMAS ismissing. Troubleshoot the power path.


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132 Fastlink



TSG data quality at Tx modules 0

Two Tx modules are used for fastlink data transmission: one stationary Tx module for theuplink to the rotating part, and one rotating Tx module for the downlink from the rotating tothe stationary part. Before starting troubleshooting for data quality, perform the TSG for thefastlink connections first.


a) if the yellow LED is “off” -> missing signal from Transmitter, or rotating

data ring defective, or stationary receiver carrier defective. Continue withstep 8.

b) if the orange Sync LED is on, but with reduced brightness -> check qual-ity of signal. (TSG data quality at Rx modules / p. 133)


8 • Check the rotating data ring (fastlink path). Refer to (How to check the trans-mitting antenna / p. 135) and readjust the stationary receiver carrier.

a) Measure the resistance of the rotating data ring (fastlink uses the outer-most structure). If resistance not o.k. -> replace the data ring.

Call HSC before replacing the data ring.

b) Adjust the stationary receiver carrier. If the error still persists, continuewith step 9.

9 • Check the connection from Rx to UMAS.

a) If red Error LEDs at UMAS are “on” -> missing signal from Rx module, orbroken/dirty fiber optic connection, or UMAS defective. Clean the fiberoptic cable (Cleaning a fiber optic cable / p. 114). If LEDs at UMAS arestill “on”, establish the original connection and continue with step 10.

10 • Use spare fiber optic cable between Rx module and UMAS.

a) If the red LEDs at UMAS are still “on” -> Rx module or UMAS defective.

Continue with step 11.

b) If the LEDs are “off” now -> Replace the fiber optical cable.

11 • Swap the Rx module with another one and check the LEDs at the Rx moduleand UMAS.

a) If LEDs on UMAS are still “on”-> replace the UMAS.

Step Action

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Fastlink 133


Tab. 53 TSG data quality at Tx modules

TSG data quality at Rx modules 0

First ensure that the quality of the data signal at the Tx module is OK (see above). Whenplugging the fiber optic cable into the Tx module, there must be a noticeable increase inlight intensity at the orange Sync LED on both the Tx and Rx modules. This condition canchange at various gantry angular positions.

Tab. 54 TSG

Step Action

1 • Unplug and Plug the fiber optic cables at the Tx module.

a) if the Sync LED shows reduced intensity (e.g. due to blinking at a highrate) -> UMAR/UMAS output broken, or broken/dirty fiber optic connec-tion from UMAR/UMAS, or Tx module broken. Clean the fiber optic cable(Cleaning a fiber optic cable / p. 134). If LED still shows reduced inten-sity, continue with step 2.

2 • Check the UMAR/UMAS output using a spare fiber optic cable.

a) Connect UMAR/UMAS to the corresponding Tx with the spare fiber opticcable. If the orange LED is o.k. now -> replace the fiber optic cablebetween UMAR/UMAS and Tx module.

b) if the orange LED still shows reduced light intensity (with spare cable

installed), -> UMAR/UMAS or Tx module defective. Continue with step 3.3 • Check the UMAR/UMAS output using the indicator on any other Tx module.

a) Connect UMAR/UMAS to any other TX module within the system, usingthe spare fiber optic cable. If the Sync Led at the temporarilly used Txmodule shows also reduced intensity -> replace UMAR/UMAS.

b) if Sync Led on the temporarilly used Tx module shows a noticeableincrease in light intensity-> replace the corresponding Tx module.

Step Action

1 • Unplug and plug the fiber optic cables at the corresponding Tx module.

a) if the Sync LED at the Rx module shows reduced intensity (e.g. due to

blinking at a high rate) -> Tx module (output) broken, or broken DataRing, or Rx module broken, or receiver carrier defective. Continue withstep 2.

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134 Fastlink



Tests for data transmission 0

Cleaning a fiber optic cable

The cable's performance may degrade because of dust or dirt covering the input core inthe cable’s receptacle.

2 • Check the RX module/s.

a) Swap the corresponding Rx module with any other Rx module (e.g. use

a Rx module from Data Path A) and check the Sync LED. If the errormoved to the temporarilly used Rx module, -> replace the Rx module.

b) if the orange LED still shows reduced light intensity, swap back the mod-ules and continue with step 3.

3 • Check the data ring (How to check the transmitting antenna / p. 135) andreadjust the receiver carrier (refer to the replacement of parts section).

a) If resistance of the microstrip antenna is o.k., replace the parts in the fol-lowing order, after adjusting the receiver carrier -> 1. Tx module, 2.receiver carrier, 3. rotating data ring.

b) If resistance of microstrip antenna is not o.k. -> replace the Rotating

Data Ring.Call HSC before replacing the data ring.

Step Action

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Fastlink 135


Fig. 61: Cleaning optical connectors

Fastlink Test

The fastlink test within the Service Platform is a quick check for the fastlink path.

Select: Local Service->Sys.Communication->Fastlink

This test has to pass without any errors determined by the counters.

If errors are found with this test, refer to TSG for the fastlink connections in this section.

How to check the transmitting antenna

The structures of the fastlink data rings (stationary and rotating) can be measured with adigital multimeter. The structures can be measured next to the transmitters as shownbelow, and at the terminals shifted 180 degrees (same test points at opposite site of dataring). The results may be slightly different ~1 Ohm.

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136 Fastlink



1. Use a digital multimeter to measure the resistance at the following test points:

Fig. 62: Test points for data ring

NOTE Measuring the resistance is important to find an interrupt orshort circuit in the structure. The nominal values shouldserve as a guideline. If the measured values are out of toler-ance, call HSC before replacing the data ring.

Measuring the fiber optic signal along the link

The fiber optic cable power at the fiber optic output of the slip ring Rx module has to be high

enough for reliable data transmission. The fiber optic receivers in the UMAR, slip ring Tx/Rxmodules, and UMAS have built-in signal level detectors that report an error when the signalfalls below a safe minimum level. However, for error identification it is important to know ifthe problem is the incoming signal or the receiving part itself. It may be possible that thepower delivered via fiber optic cable to the input is high enough, however, the fiber opticreceptacle in the receiver module is covered with dust or dirt, and the incoming light does

Measure between Nominal value

TP1 and TP3 79 Ohm +/- 1 Ohm

TP2 and TP4 79 Ohm +/- 1 Ohm





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Fastlink 137


not reach the destination. The fiber optic signal can be measured at any point in the linkusing an optical power meter (e.g. the HP 8410A or HP 8153A). The power level of the fiberoptic cable should be at least -9 dBm avg. at 850 nm into a 62.5/125 MMF fiber optic cable.

The modulation signal (fiber optic cable extension ratio) can be optimally measured with an

oscilloscope and a fiber optic probe, e.g. Tektronix 6701B. The signal amplitude is typically400µW.

Note: A fiber optic cable mounted in the gantry is difficult to measure with the above men-tioned instruments unless the cable is fully released from the gantry cable tree. To avoidthis operation, you may use the delivered spare fiber optical cable and the adapter toextend a cable end up to the measuring instrument. Consider additional loss in the sparecable to correct the final result.

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138 Rotating Gantry



6-6RotatingGantry

General 0

Safety 0





Notes 0

This section contains information about isolating different problems in the rotatingpart of the gantry.

• Section “General” -> General information

• Section “CAN Bus” -> Guided steps for troubleshooting CAN bus problems

• Section “Stop Report” -> Guided steps for troubleshooting Stop Report problems

• Section “Rotating controller” -> Rotating controller tests

• Section “System test” -> System tests (DOM functional, X-ray timeout)



Prerequisites 0

Documents

n.a



• Multimeter

• Scope


CAN Controller area network

tbd To be done

TSG Troubleshooting guide

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Rotating Gantry 139


CAN Bus 6.1

CAN bus rotating part

The UMAS is the master controller for the CAN bus of the rotating part. The CAN bus con-sists of a closed loop which is routed through certain rotating components. The terminalresistor of the CAN bus has a value of 120 ohm and is located inside of the UMAR. The 2wires of the loop are named CAN_L and CAN_H. The CAN bus wires CAN_L and CAN_Hare routed from the UMAS via the rear slip ring (2 tracks) to the UMAR. At the UMAR, theCAN bus wires are routed through XGR A/B, XDC A/B and the PDR.

Because the CAN bus is a hard-wired loop connection (refer to figure), the resistance ofthe loop can be measured using a multimeter. The resistance at plug X401 on cable W399between pin 2 and 10 must be 120 +30/-10 ohm. Also check that the 2 CAN wires(CAN_l/CAN_H) are insulated from ground. All affected CAN bus components are indi-cated in the figure below.

Fig. 63: Can bus overview - rotating part of the gantry

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140 Rotating Gantry



TSG CAN bus (rotating part) 0

Tab. 56 CAN bus troubleshooting

Step Action

1 • Switch system off and press service switch S1 in PDC-A to switch off gantrypower completely.

2 • Remove plug X401 from UMAS. Measure the resistance at plug X401 oncable W 399 between pin 2 and pin 10 (CAN Bus / p. 139).

a) If the measured resistance value is 120 +30/-10 ohm -> wiring from plugX401 cable W399 to the 120 ohm bus terminator inside of the UMAR isok -> continue with item 3.

b) If the resistance value is not 120 +30/-10 ohm -> continue with item 4.

3 • Measure the resistance at plug X401 on cable W 399 from pin 2 and pin 10

against system ground (CAN Bus / p. 139).a) If the resistance value is > 10 Kohm -> insulation on CAN_H and CAN_L

wires against system ground is ok -> no further action necessary.

b) If the resistance value is about 0 ohm -> insulation for CAN_H andCAN_L against system ground is not ok (short circuit to ground) -> con-tinue with item 5.

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TSG CAN bus to XGS 0

CAN bus to XGS

The UMAS is the master controller for the CAN bus to the XGS. The CAN bus consists ofa closed loop which is routed through XGS-A in PDC-A and XGS-B in PDC-B. The terminalresistor of the CAN bus has a value of 120 ohm and is located inside a dongle. The dongleis plugged in at XGS-B X3. The 2 wires of the loop are named CAN_L and CAN_H. TheCAN bus wires CAN_L and CAN_H are routed from the UMAS to XGS-A and XGS-B.Because the CAN bus is a hardwired loop connection (see drawing below) the resistanceof the loop can be measured using a multimeter. The resistance at plug X400 on the UMAS

4 • Remove plug X305 from UMAR. Measure the resistance at plug X305 on theUMAR between pin 2 and pin 10 (CAN Bus / p. 139).

a) If the resistance value is 120 +30/-10 ohm -> CAN bus connectionbetween plug X305 on cable W550 and plug X401 on cable W399 has aproblem.

-> check wiring from plug X305 on cable W550 to plug X1 on the slip ringpin 2/10 for bad contact or broken wires.

-> check wiring from plug X401 cable W399 to plug X2 on slip ring pin2/10 for bad contact or broken wires.

-> If above cable wiring is ok -> the problem is at the back slip ring (mea-sure the continuity between plugs X1 and X2 pin 2/10 on the slip ring ,check/change defective brushes....).

b) If the resistance value is not 120 +30/-10 ohm -> remove plugs X302,

X303, X307, X301, and X300 in sequence. At each of these plugs on theUMAR, measure the resistance between pin 4 and 11 until 120 +30/-10ohm can be measured.

-> If 120 +30/-10 ohm can be measured -> the CAN bus problem isbetween the last plug measured and the previously measured plug ->find by ohm measurement which part is defective and change the defec-tive part.

5 • Remove plug X305 from UMAR. Measure the resistance at plug X401 oncable W399 pin 2/10 against system ground (CAN Bus / p. 139).

a) If the insulation problem still exists -> the insulation problem is between

plug X305 on cable W550 and plug X401 on cable W399. Remove partslocated between above mentioned plugs in sequence to find the insula-tion problem.

b) If the insulation problem no longer exists -> the problem is somewhere inthe rotating part between UMAR and the connected components. Isolatethe problem by measuring at plug X305 pin 2/10 on UMAR to systemground while removing plug X300, X301, X307 X303, and X302 insequence.

Step Action

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142 Rotating Gantry



between pin 2 and 10 must be 120 +30/-10 ohm. Additionally, check that the 2 CAN wires(CAN_l/CAN_H) are insulated against ground. All affected CAN bus components are indi-cated in the figure below.

Fig. 64: CAN bus overview for XGS

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Rotating Gantry 143


Tab. 57 CAN bus troubleshooting

Step Action

1 • Switch system off and switch off system power using the onsite off/on switch(power of XGS-A/B is switched off).

2 • Remove plug X400 from UMAS. Measure the resistance at plug X400 oncable W55 between pin 2 and pin 10.

a) If the measured resistance value is 120 +30/-10 ohm -> wiring from plugX400 on cable W55 to the 120 ohm bus terminal at X3 on XGS B is ok-> continue with item 3.


3 • Measure the resistance at plug X400 on cable W55 from pin 2 and pin 10against system ground.

a) If the resistance is > 10 Kohm -> insulation of CAN_H and CAN_L wires

against system ground is ok -> no further action necessary.

b) If the resistance is about 0 ohm -> insulation of CAN_H and CAN_Lagainst system ground is not ok (short circuit to ground) -> continuewith item 8.

4 • Remove plug X4 from XGS-A. Measure the resistance at plug X4 on XGS-Abetween pin 2 and pin 10.

a) If the resistance value is 120 +30/-10 ohm -> CAN bus connectionbetween plug X4 and X400 on cable W55 has a problem.

-> check cable W55 for bad contact or broken wires.


5 • Remove plug X3 from XGS-A. Measure the resistance at plug X3 on thecable W54 between pin 2 and pin 10.

a) If the resistance value is 120 +30/-10 ohm -> check plugs X3 /X4 onXGS-A for bad contacts; otherwise, change XGS-A.


6 • Remove plug X4 from XGS-B. Measure the resistance at plug X4 on XGS-Bbetween pin 2 and pin 10.

a) If the resistance is 120 +30/-10 ohm -> check cable W54 for bad contact

or broken wire; otherwise, change cable W54.b) If the resistance is not 120 +30/-10 ohm -> continue with item 7.

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144 Rotating Gantry



7 • Remove plug X3 (including the 120 ohm bus terminal) from XGS-B and mea-sure the resistance at plug X3 (dongle) between pin 2 and pin 10.

a) If the resistance value is 120 +30/-10 ohm -> check plugs X3/X4 onXGS-B for bad contacts; otherwise, change XGS-B.

b) If the resistance value is not 120 +30/-10 ohm > change dongle plug X3.

8 • Remove plug X3 from XGS-A. Measure the resistance at plug X3 on cableW54 pin 2/10 against system ground.

a) If the insulation problem still exists -> the insulation problem is betweenplug X3 on cable W54 , XGS-B and dongle plug X3 on XGS-B. Removelisted parts in sequience to isolate the insulation problem.

b) If the insulation problem no longer exists -> the insulation problem isbetween plug X400 on the cable W55 and plug X3 on XGS-A. Remove

listed parts in sequence to isolate the insulation problem.

Step Action

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Rotating Gantry 145


Stop report loop 6.2

The stop report loop is a made up of a number of contacts connected in series and fed with24 V via Relay K8. Relay K6 is normally energized as long as power is available at theUMAS. The stop loop is then set by the firmware closing K7 for 100 ms. When all stop con-

tacts are closed, K8 will energize and be held on by its self-holding contacts. Opening oneof the stop contacts will cause K8 to release.

NOTE The Stop Report Loop LEDs on UMAS are still under con-struction. For this reason the troubleshooting describedbelow is only valid in a limited manner for the current systemstate.

TSG stop report loop 0

If the stop report loop does not close, you may use the S8 switch on the UMAS for trouble-shooting. By activating S8, the K8 contact is bridged and 24 V (30 mA) is supplied to thestop report loop. Check down the LEDs on the UMAS if the LED status is on or off. The firstLED found which is not on indicates an open loop and therefore the direction of trouble-shooting. For example, if LED “SR PFront” is on but “SR PDC” is the first LED switched off,the loop to the upper front segment is open. In this case you can measure the continuity ofthe upper front segment components until the problem (open loop) is found.

NOTE To troubleshoot some of the components of the stop report

loop, it is necessary to have a 15 pin SUB D (male and female)plug available.

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146 Rotating Gantry



Fig. 65: Stop circuit

Tab. 58 Stop report troubleshooting

Step Action

1 • Switch on service switch S8 on UMAS (use a small tool to switch on S8).

2 • Check status of the following stop report loop LEDs on UMAS in the followingascending order.

a) SR PFront

b) SR PDC

c) SR UMAS

d) SR PRear

e) SR Con-Box

f) SR CTRLRot

If a LED is on -> loop to the belonging component loop is ok. The first LEDwhich is switched off indicates that the corresponding component loop isopen. Troubleshoot in this direction.

a) If all LEDs are off -> continue with item 3.

b) If the first LED which is not lit is SR PFront -> continue with item 4.

c) If the first LEDs which is not lit is SR PDC -> continue with item 5.

d) If the first LED which is not lit is SR UMAS -> continue with item 6.

e) If the first LED which is not lit is SR Con-Box -> continue with item 7.

f) If the first LED which is not lit is SR CTRLRot -> continue with item 8.

g) If all LEDs are on -> continue with item 9.

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Rotating Gantry 147


3 • UMAS internal problem or missing 24 V at UMAS.

a) Check if 24 V LED is lit on UMAS -> if not, 24 V from PD-A is missing

b) Press push button S5 (activates K11) and check if LED “SR PFront”switches on.

c) Change UMAS

3 • Open stop loop at upper front segment components (panels, display, MV45,wiring). Measure the continuity of the loop in sequence until the problem isfound.

a) Measure the continuity from pin 1 to 14 at plug X403 on cable W357.

Measure the continuity from pin 1 to 14 at plug X307 on cable W250.

Measure the continuity from pin 1 to 14 at plug X2 on cable W252

Measure the continuity from pin 1 to 14 at plug X2 on cable W254Measure the continuity from pin 1 to 14 at plug X2 on cable W256

4 • Open stop loop to XGS-A or XGS-B

a) Measure the continuity between plug X400 on cable W54 pin 1/9 to X4(W54) pin 1/9.

b) Switch service switch S8 on the UMAS to off (normal position).

Install Sub D plug with bridged pin 1 and 9 onto plug X3 on XGS-A (sim-ulate stop loop to XGS-B). Switch system on and check whether LED“SR PDC” is on or not.

-> If LED SR2 is on -> open loop to XGS-B

-> If LED SR2 is still off -> open loop in XGS-A

5 • Open stop loop from internal UMAS FPGA. There are different reasons thatthe FPGA opens the stop loop. Perform a restart and/or check logbook forother error messages that have caused the FPGA to open the stop loop.

a) Switch system off. Press service switch S1 in PDC A to switch UMAS off.Restart system.

b) Check logbook for error messages that have caused the FPGA to openthe stop loop. Follow the troubleshooting instructions described in theerror messages.

c) Change UMAS.

6 • Open stop loop of the back ring components (panels, MV45, wiring). Mea-sure the continuity of the loop in sequence until the problem is found.

a) Measure the continuity from pin 1 to 14 at plug X404 on cable W358.

Measure the continuity from pin 1 to 14 at plug X308 on cable W251.



Step Action

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148 Rotating Gantry



7 • Open stop loop to the control box. Measure the continuity of the loop insequence until the problem is found.

a) Measure the continuity from pin 1 to 9 at plug X402 on cable W51 .8 • Open stop loop from the rotating part of the gantry. First measure the conti-

nuity between plug X401 on the UMAS and plug X305 on the UMAR. Thenexclude components using of a Sub D plug with bridged pins 1 and 9.

a) Measure the continuity between plug X401 on cable W399 (pin 1/9) viathe slip ring part to plug X305 on cable W550 (pin 1/9).

b) Switch off service switch S8 on the UMAS (normal position).

Install Sub D plug bridged between pin 1 and 9 in sequence onto plugsX302, X303, X301, and X300 on the UMAR (simulate loop to the con-nected components).

Switch system on and check if the stop circuit is ok when the bridged SubD plug is installed. Perform above steps on all above mentioned plugs.

-> If the stop loop closes -> the problem is caused by the componentwhich is normally connected to the plug where the dummy Sub D plug isconnected at the moment.

-> If the stop loop does not close -> FPGA stop report loop on UMAR isopen. There are different reasons that the FPGA opens the stop loop.Check the Eventlog for error messages that have caused the FPGA toopen the stop loop. Follow troubleshooting instructions given in the errormessages to continue.

-> Change UMAR.

Step Action

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Rotating Gantry 149


Rotating controller 6.3

DOM 0

The functionality of the Dose Modulation Control is tested. It contains the following sub-tests: Self-Test: The self-test of the DOM controller is performed via the test interface.

Performing the DOM test

1. Select Local Service -> Test Tools -> Rot. Controller -> DOM

2. Select unset all.

3. Select relevant tests.


Tab. 59 DOM test

COC (Tube collimator) 0

Tube collimator test function

The tube collimator is used for:

• collimation of the fan beam

• improving image quality (beam hardening) with movable head filter

• measuring the dose value -> PHI-Z-monitor

Step Action

1 If test fails, change UMAR.

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150 Rotating Gantry



• controlling the flying focus position in the tube -> Phi-Z-monitor

To test the function of the tube collimator, the “COC” test is available in Local Service. Thetest checks the function of the Phi-Z monitor in the tube collimator as well as the tube col-limator function itself.

PHI-PSD Signal test (lab only): A positive and negative current can be selected in the testplatform. The selected current is applied via an amplifier to the A/D converter. The outputof the A/D converter is checked.

Z-PSD Signal test (lab only): A positive and negative current can be selected in the testplatform. The selected current is applied via an amplifier to the A/D converter. The outputof the A/D converter is checked.

Collimator test: No actual mechanical blade movement test, instead encoder values oflast INIT or last fatal TCO error (forces a TCO INIT run) are used. If values are in tolerance,this test was successful. Test can be used to check if the last encoder values were ok. Itdoes not test the actual TCO status - see TSG instructions on how to check the actual blademovement.

Filter test: Test moves the head filter to the in/out end position indicated by two LEDs. Rep-etitions can be selected and sporadic problems detected - see TSG instructions.

Tube collimator TSG

Tab. 60 Tube collimator TSG

Step Action

1 Switch gantry off/on (COMP/ON -> SYS/ON) to trigger a gantry INIT. During

INIT, check if the TCO blades are moving and if the movable head filter positionLEDs “F1 POS 1” and “F1 POS 2” are alternately switching on/off (in/out endposition of head filter indication).

- if above conditions are fulfilled -> continue with item 2

- if the TCO blades are not moving or seem to move incorrectly -> continue withitem 3

- if TCO head filter LEDs are not alternately switching on/off -> continue withitem 4

2 Check Eventlog for error messages (power supply, etc.) during INIT test

if error messages are found -> continue troubleshooting as described in theerror message text

if no error message is found -> no further action

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Rotating Gantry 151


3 Check Eventlog for error messages (power supply, etc.)

if error messages are found -> continue troubleshooting as described in the

error message textif no error message is found -> change TCO

4 Select some repetitions in the COC filter test and check the Eventlog for theerror messages (power supply, etc.) that appeared during the filter test.

if error messages are found -> continue troubleshooting as described in theerror message text

if no error message is found -> change TCO

Step Action

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System Tests 6.4

DOM functional 0

For the dose modulation test the system phantom is used. After the phantom is positionedcorrectly two measurements (with both systems) are performed. The first measurement isperformed without dose modulation, the second with dose modulation. After each mea-surement the effective mAs-product is read from generator table (control table). Theimages are reconstructed and displayed. After the reconstruction, an ROI is positioned ineach image and the noise is retrieved. A computation concerning noise and mAs-productof both images determines whether the dose modulation works correctly or not. If a tubearcing has occurred, the test is not valid and must be repeated. The test can be done forboth systems separately.

Function: The DAS controller generates a DOM data frame for use in dose modulationfunctions. A DOM frame is a compressed version of any IRS reading sent to UMAR via

Fastlink. The UMAR builds an angular attenuation profile used to modulate on-line the radi-ation profile (Dose) applied to the patient. From the radiation profile, the filament data arecalculated and sent via Fastlink to the XGR (FilPower). Most of the DOM function in UMARis software.

Performing the test

1. Select Local Service -> Test Tools -> Rot. Controller -> COC



4. Click GO and follow the instructions in the dialog. The test is terminated automatically.If a test fails, follow the TSG described next.

DOM functional TSG

Tab. 61 DOM functional TSG

Step Action

1 Perform Dom functional test 5 times.

-> if the test is out of tolerance at least 3 times -> continue with item 2.

-> if test is not out of tolerance at least 3 times -> no action necessary

2 Perform DOM test “Local Service -> Test Tools -> Rot. Controller -> DOM”

-> if DOM test is out of tolerance -> change UMAR

-> if DOM test is ok -> continue with item 3.

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Rotating Gantry 153


X-ray timeout test 0

This test checks if the scan is switched off after 108% scan time. Normally a scan isswitched on/off only from the XC (X-ray release) signal, which is sent at scan start fromUMAR to XGS/XGR. For safety reasons, a timer in XGS/XGR is started as soon radiationis switched on (> 20 kV) triggered from the XC signal. If the XC signal is not switched offbefore the internal XGS/XGR timer exceeds its 108% limit, the scan is switched off by theinternal timer. If the test fails at XRS_113, (XGR Scan Time Exceeded) is sent to theEventlog.

Performing the test

1. Select Local Service -> Test Tools -> System tests -> Xray timeout




If a test fails, follow the TSG described next.

X-ray timeout TSG

Tab. 62 Xray timeout TSG

3 Check image quality from normal scans without selected DOM function.

-> if image quality is ok -> UMAR <-> DMS communication ok -> continue with

item 4.-> if image is not ok -> troubleshoot Fastlink communication UMAR -> DMS(Fastlink / p. 121).

4 Troubleshoot Fastlink communication UMAR -> XGR (Fastlink / p. 121).

Step Action

Step Action

1 Check the Event log for the XRS_113 error message. Follow the instructionsgiven in the error message text.

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154 Stationary Gantry



7-7Stationary Gantry

General 0

Safety 0





Notes 0

This section contains information about isolating different problems in the station-ary part of the gantry.

• Section “General” -> General information

• Section “CANopen Bus” -> Guided steps for troubleshooting CANopen bus prob-lems

• Section “Stationary controller tests ” -> Information about staionary controller tests



Prerequisites 0

Documents

n.a



• Multimeter

• Scope


CAN Controller area network

TBD To be done

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Stationary Gantry 155


CANopen Bus 7.1

TSG CAN open bus 0

The UMAS is the master controller for the CANopen bus. The CANopen bus consists of aclosed loop which is routed through certain components (refer to diagram). The terminalresistors of the CANopen bus have a value of 120 ohms and are located inside the SCRand the PHS.

In addition, the control box is connected via a “repeater” (part of the UMAS board) to theCANopen bus. Therefore, the control box contains a 120 ohm terminal resistor as well.

NOTE The CANopen bus can be checked by measuring the resis-tance of the CANopen circuit.

Fig. 66: CANopen bus

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Tab. 64 Sequence to measure the CANopen loop resistance:

Tab. 65 Pin list for CANopen bus

Step Action

1 • Switch off the system and press the service switch S1 in PDC A to switch offgantry power.

2 • Remove one of the CANopen circuit connectors.

For troubleshooting, it is recommended to remove a CANopen circuit con-nector located in the middle between the two terminal resistors (refer to step18 of the CANopen pin list).

Measure the resistance in both directions from the CANopen circuit. Pluglocated at the component and the plug located at the cable.

3 • Measure the CANopen loop resistance between the CANopen_H pin andthe CANopen_L pin (refer to the CANopen pin list).

The resistance between the CANopen_H pin and the CANopen_L pin

must be 120 +30/-10 ohm.

4 • Measure the ground resistance of the CANopen_H pin and the CANopen_Lpin against system ground.

Note: The CANopen circuit must be isolated against system ground.

The ground resistance must be greater than 10 Kohm.

5 • If the measurement values (in both directions) are in tolerance, the CAN-open circuit is o.k.

• If a measurement value is out of tolerance, remove the next CANopenconnector in the direction where the measurement value is out of tolerance.

Repeat the measurements from step 4 and step 5.

Step Component Connector CANopen_Hpin

CANopen_Lpin

Remark

1 SCR X5 7 2 120 ohm

2 WCS X4 1 2

3 WCS X3 1 2

4 UMAS X472 1 2

5 UMAS X404 15 2

6 X308 15 2

7 PRR X1 15 2

8 PRR X2 15 2

9 PRL X1 15 2

10 PRL X2 15 2

11 MV45 X1 15 2

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12 MV45 X1 16 4

13 PRL X2 16 4

14 PRL X1 16 4

15 PRR X2 16 4

16 PRR X1 16 4

17 X308 16 4

18 UMAS X404 16 4

17 UMAS X403 15 2

18 X307 15 2

19 PFR X1 15 2

20 PFR X2 15 2

21 DF X1 15 2

22 DF X2 15 2

23 PFL X1 15 2

24 PFL X2 15 2

25 MV45 X1 15 226 MV45 X1 16 4

27 PFL X2 16 4

28 PFL X1 16 4

29 DF X2 16 4

30 DF X1 16 4

31 PFR X2 16 4

32 PFR X1 16 4

33 X307 16 4

34 UMAS X403 16 4

35 UMAS X471 1 2

36 PHS X702 7 2 120 ohm

CANopen bus repeater (part of the UMAS board)

37 UMAS X402 10 2

38 Control Box X1 10 2 120 ohm

Step Component Connector CANopen_Hpin

CANopen_Lpin

Remark

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Stationary controller tests 7.2

The system has to be in standby mode to perform the following controller tests. Some con-troller tests, such as GSV, PHS, and CPI are not available or functioning with VA10.

Prerequisites 0

n.a

Master stationary (MAS) test 0

Test of foot switch and external trigger

1. Select Local Service -> Test Tools -> stat.Controller -> MAS

2. Select one or all MAS tests.3. Click “Go” on the virtual user panel. Follow the instructions in the dialog.


If check fails -> follow instructions in the table below.

Tab. 66 MAS TSG

Gantry panel control (GPC) test 0

Test of control box, gantry panel, and gantry display.

1. Select Local Service -> Test Tools -> stat.Controller -> GPC.

2. Select one or all GPC tests.

3. Click “Go” on the virtual user panel.

4. Click the Start button at the control box and follow the instructions in the dialog.


Tab. 67 GPC TSG

Rotation control (ROT) test (only max. speed limit test, 0.33 sec.) 0

Test of speed limit 0.33 sec.

1. Select Local Service -> Test Tools -> stat.Controller -> ROT.

2. Select one or all ROT tests.

Step Action

1 • Check/change footswitch or cable connection.

Step Action

1 • Change part that was functioning incorrectly.

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3. Click “Go” on the virtual user panel.

4. Click the Start button at the control box and follow the instructions in the dialog.


Tab. 68 GPC TSG

Step Action

1 • Check for ROT error messages in the Eventlog. Follow the instructions givenin the error message.

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160 Cooling System



8-8Cooling System

Cooling System 0

Water Cooling 0

General

The water cooling system provides heat dissipation for the gantry electronics and X-raytube to a central facility chilled-water system or to an “Air-Water Split Cooling Unit” (option).The internal air temperature of the gantry is regulated by a motor-driven 3-way bypassvalve on the incoming cold water and by a variable-speed blower fan on an air/water heatexchanger (radiator) where the facility-chilled water flows through. Both are controlled byan electronics box containing control boards and connected to sensors for the water andair. The electronics box connects to the system via the CANopen bus. The fan unit containsits own fan motor control board that connects to the electronics box. The blower in the lowerright gantry stand cools all rotating parts; there are no other fans in the rotating gantry.

A condensate-collection system collects condensed water below the radiator and automat-ically pumps it away to a drain. The condensate pump connects electrically to the electron-ics box.

If the temperature in the gantry or the temperature of the incoming water exceeds limitsaccording to the sensors, the electronic box will issue messages via the CANopen bus tothe UMAS that then appear in the EventLog of the ICS.

For sites using the Water-Air Split Cooling Unit, an interface to it is provided on the elec-tronics box (X6).

The following diagrams are from the Function Description.

Fig. 67: Water Cooling Overview

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Cooling System 161


Fig. 68: Water Cooling System in Gantry

Fig. 69: Gantry water cooling circuit

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162 Cooling System



Fig. 70: Water Cooling Electronic Box Block Diagram

TSG Water Cooling

General troubleshooting process steps:

1. If possible, try to determine if the problem is EXTERNAL or INTERNAL to the gantry bylooking at the EventLog, Current Cooling State shown in Table T00, and LEDs on theelectronics box. If the problem appears to be external, seek possible resolution in hos-pital/facility-chilled water system or with Split Air/Water Unit (Option), depending onwhich is used at the site. Continue to evaluate the internal gantry conditions if the exter-nal ones are verified as OK or cannot be determined immediately.

2. If the problem is INTERNAL to the gantry, look at the EventLog, Current Cooling State

shown in Table T00, observe the LEDs on the electronics box, and use the laptop ser-vice connection to the electronics box described below.

3. Replace suspected defective parts.

NOTE Always be aware that if you open the cooling pipes, you mustprepare for preventing spills and refilling. If connected to thehospital/facility cooling system, contact the facility engineer-ing personnel!

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Cooling System 163


Information sources

The following sources of information about the source for cooling problems are available:

1. Messages in the EventLog:

Review the EventLog for warning and error messages from the WCS and troubleshootbased on these errors. You can filter the EventLog on the text “COOLING” to see only cool-ing errors.

If you cannot access the EventLog for any reason, due to a faulty ICS or CANo-pen connection for example, you can connect a service laptop directly to the cool-ing electronics box (# 4 below).

The following two INFORMATION messages in the EventLog are useful to determine pos-sible changes in the cooling conditions, even if there are no warning or error messages.

NOTE These messages are INFORMATION-priority and will not dis-play in the EventLog Viewer unless you have INFO messagesturned on. Also, they are generated only when a certainamount of change has occurred in one of the measured val-ues. For a readout of the current state of these values, seeStep 2, “Table T00” shown below.

Message about the ENVIRONMENT/PRIMARY SIDE:

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164 Cooling System



Fig. 71: Message MAS220

Message about the COOLING SECONDARY (GANTRY) SIDE:


To determine what value is being displayed, look at the P1 value in the actual message

shown in the EventLog and find this HEX number on the list of “Parameter 1: SupervisionID numbers” in the expanded message (above). P3 & P4 show the actual value in HEX.

NOTE It is necessary to convert HEX to decimal to read the value.Use the Windows Calculator in the Scientific mode (WinXPPrograms > Accessories > Calculator > View > Scientific).Click the HEX button, enter the values of P3 and P4 in order,then click the DEC button. Remember that temperature val-ues are given in 1/10th degree (e.g., 247 = 24.7 degrees C).

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Cooling System 165


2. Current system cooling status using table T00:

Using the Service Software function Control > Table Load/Modify, open table “T00” from“Volatile.” The current state of the various sensors is shown in the data fields of T00. Com-pare this to the nominal values shown in the following screen-shot to determine if the actual

values displayed reveal any strong deviations and troubleshoot these.

NOTE DO NOT change the values in any of the tables!

Fig. 73: T00 table for water cooling

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166 Cooling System



3. LEDs on WCS electronics box:

The three LEDs on the left side of the electronics box are status indicators. In the normalmode of operation, only the green LED (H1) flashes. The yellow LED (H2) is illuminated ifa warning (e.g., temperature out of tolerance) occurs, and also briefly whenever the control

board is switched on (initialization). During a fault condition (e.g., fan error), the red LED(H3) is on continuously.

4. Additional information: Laptop service connection to electronics box

Note: All messages mentioned below are also sent to the Eventlog. Therefore the laptopconnection should be used only by someone who is familiar with a terminal emulator pro-gram.

Connect the laptop PC serial port to the service connector on the electronics box with anull-modem cable and running a terminal emulator program such as HyperTerminal.

Example:

>sta

>UpTm: 54:46 C:1 E:0 LE:250 I/Yf:6000/290 LA:200 I/Ym:0/0 Pos:0WE:

100 WA:150 FS:584

The number after the letter E: indicates the warning or error message code.

E:0 indicates no warning or fault.

Warning Alarms (YELLOW LED on electronics box illuminated):

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Cooling System 167


Error Alarms (RED LED on electronics box illuminated):

Code Warning messages via the laptop

10 /110

Cooling unit exhaust air temperature (into gantry) too low

• Control valve - electrical connection is faulty - Check wiring connection at

valve.

• Control valve isn’t working - Try turning the valve knob manually; see if itresponds by returning to its original position. If so, probably OK (repeat sev-eral times). If it does not return to its original position, replace valve driveunit, electronics box, sensors, valve.

11 /111

Exhaust air temperature of cooling unit (into gantry) is too high

• Same cause/action as code 10 above.

20 /120

Hospital supply water temperature is too low (<4 degrees C)

• Look for a thermometer on the hospital's incoming water lines and verify

coolant is 4-12 degrees C. Contact hospital facility engineers if out of range.If hospital water supply is really OK, check/replace sensor for incoming watertemperature.

21 /121

Hospital supply water temperature is too high (>12 degrees C)

• Look for a thermometer on the hospital's incoming water lines and verifycoolant is 4-12 degrees C. Contact hospital facility engineers if out of range.Check if the hospital's water is filtered, and if so, if the water filter is clogged(briefly open bypass valve). If the hospital 's water supply is really OK, checksensors for the hospital's water temperature and flow by shutting off incom-ing water valve (red handle 90 degrees) and monitoring the sensors with

Table Load/Modify of Table T00: temperature and flow indications shouldrespond.

30 /130

Gantry temperature is too low (< 22 degrees C).

• Gantry temperature regulation is not working properly. Replace: controlvalve drive / control valve, electronics box, sensors.

31 /131

Gantry temperature is too high (>30 degrees C).

• Gantry temperature regulation is not working properly. Verify sensor connec-tion (if not connected, this error results). Replace: control valve drive / controlvalve, electronics box, sensor, fan (if not blowing).

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168 Cooling System



Air Cooling 0

General

The air cooling system provides heat dissipation for the gantry electronics and X-ray tubeby circulating air from the exam room through the gantry and exhausting it back into theroom. The air intake is on the left side of the gantry left stand and the exhaust is from thetop of the gantry housing. The internal air temperature of the gantry is regulated by a vari-able-speed blower (fan) motor. There are no other fans in the rotating gantry - the blower

Code Warning messages via the laptop

210 Error in fan controller

• Fan connection to the electronics box is not connected. Check electrical con-

nection between fan and electronics box (connectors 1X1 and 1X2).

• Fan bearing has seized. Check that fan rotor turns easily - DISCONNECTFAN POWER before touching the fan blades.

• Controller or fan has failed - replace fan unit.

220 Water level in condensate pan is too high

• Check water level in condensate pan, function of condensate pump andswitch, and make sure that the clear hoses are OK. Verify electrical connec-tion of condensate pump to electronics box (connector 1X3).

230 Fan speed too low

• Check connection between electronics box and fan (connectors 1X1 and1X2). Replace electronics box, fan unit.

1010 /1011

Sensor R1 fault: exhaust air temperature to gantry

• Check/replace sensor R1, connector 2X4.

1020 /1021

Sensor R2 fault: air inlet temperature from gantry

• Check/replace sensor R2, connector 2X4.

1050 /1051

Sensor R3 fault: water outlet temperature or flow

• Verify proper temperature and adequate flow of incoming hospital water.

Check/replace sensor R3, connector 2X4.

1060 /1061

Sensor R4 fault: water inlet temperature

• Verify proper temperature of incoming hospital water. Check/replace sensorR4, connector 2X4.

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Cooling System 169


in the lower right gantry stand provides cooling for all rotating parts. The electronics boxconnects to the system via the CANopen bus. The fan unit contains its own fan motor con-trol board that connects to the electronics box.

A differential pressure sensor provides feedback to the electronics box about the dynamic

pressure in the measurement device, which reflects the actual air flow rate. A clogged airfilter will cause this sensor to activate and issue messages that the filter needs to becleaned.

If the temperature in the air intake of the gantry exceeds limits according to the sensors,the electronics box will issue messages via the CANopen bus to the UMAS that thenappear in the EventLog of the ICS. If the gantry continues to overheat, the user is promptedto finish the current patient. A timer is started, which will shut off the gantry power after 10minutes.

The following diagrams are taken from the Function Description.

Fig. 74: Air Cooling - Overview

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Cooling System 171


NOTE These messages are INFORMATION-priority and will not dis-play in the EventLog Viewer unless you have INFO messagesturned on. Also, they are generated only when a certainamount of change has occurred in one of the measured val-

ues. For a readout of the current state of these values, seeStep 2, “Table T00” shown below.

Message about the ENVIRONMENT/PRIMARY SIDE:


Message about the COOLING SECONDARY (GANTRY) SIDE:


To determine what value is being displayed, look at the P1 value in the actual messageshown in the EventLog and find this HEX number on the list of “Parameter 1: SupervisionID numbers” in the expanded message (above). P3 & P4 show the actual value in HEX.

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172 Cooling System



NOTE It is necessary to convert HEX to decimal to read the value.Use the Windows Calculator in the Scientific mode (WinXPPrograms > Accessories > Calculator > View > Scientific).Click the HEX button, enter the values of P3 and P4 in order,

then click the DEC button. Remember that temperature val-ues are given in 1/10th degree (e.g., 247 = 24.7 degrees C).

2. Current cooling status using table T00: Using the Service Software function “TableLoad/Modify;” open table “T00” from “Volatile.” The current state of the various sensors isshown in the data fields of T00. Compare this to the nominal values shown in the followingscreen-shot to determine if the actual values displayed reveal any strong deviations andtroubleshoot these.

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Cooling System 173


Fig. 78: T00 table for air cooling

3. LEDs on WCS electronics box:

The three LEDs on the left side of the electronics box are status indicators. In the normalmode of operation, only the green LED (H1) flashes. In the event of a fault condition (e.g.,fan error), the red LED (H3) is continuously illuminated. The yellow LED (H2) is illuminatedif a warning (e.g., temperature out of tolerance) occurs. Important: It also illuminates brieflywhenever the control board is switched on (initialization).

4. Additional information: Laptop service connection to electronics box

No information is available from the cooling unit air supplier.

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174 Changes to Previous Version



9-9ChangestoPreviousVersion

Chapter Change Reason

3Disabling of the UHR comb and service switches

addedTD_Charm_11561

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Index 175


10Index

H hz_serdoc_F13G01U03M01 . . . . . . . . .8

hz_serdoc_F13G01U05M03 . . . . . . . . .8

hz_serdoc_F13G01U06M01 . . . . . . . . .8

hz_serdoc_F13G01U12M0315, 56, 100, 121, 138, 154hz_serdoc_F13G01U13M02 . . . . . . . . .8

hz_serdoc_F13G02U01M01 . . . . . . . . .9

hz_serdoc_F13G02U01M04 . . . . . . . . .7

hz_serdoc_F13G05U01M04 . . . . . . . . .9

hz_serdoc_F13G07U01M01 . . . . . . . . .7

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176 Index