060079 Meridian Surveyor

7/28/2019 060079 Meridian Surveyor

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Cover s Sof t w ar e Ver s ion 1.6x

Meridian Surveyor

User Manual

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Contents

DPN 060079 TSS (International) Ltd Issue 2.10 Page 1 of 6

CAUTIONARY NOTICES

Your attention is drawn to the following cautionary notices that apply throughout thisManual.

WARNINGThe Meridian Surveyor weighs 15.5kg. To avoid personal in jury, takeproper precautions i f you li ft or move the equipment.

WARNING

There is a danger o f serious injury from voltages inside the MeridianSurveyor. Do not remove the gyrocompass cover unless you have thenecessary skil ls and experience to perform maintenance work on asystem of this nature. Always power-off the system before you removethe cover for maintenance work.

Observe all local safety regulations as you work on the equipment.Reconnect the safety grounding straps and refit all safety covers to theequipment before you power-on the system.

WARNING

Do not dispose of by fire or compacting, as toxic fumes, dust or liquidsmay be released.

CAUTION

You wil l void the warranty if you make any modi fications to this

equipment without prior permission from TSS (International) Ltd.DO NOT modify this equipment in any way without obtainingpermission from TSS (International) Ltd.

CAUTION

The Meridian Surveyor includes precision components and bearings.To avoid causing damage to any part of the System, handle all i temswith care.

Retain the original transit cases so that you can use them to t ransportthe system when necessary. You wi ll void the warranty i f you use

improper packing during transportation.

CAUTION

Severe damage to the Meridian Surveyor can occur if you move thegyrocompass while the rotor is still spinning without the servo systemin operation.

Note that the gyro rotor continues to spin for approximately fiveminutes after you power-off the system.

To avoid potential damage to the Meridian Surveyor, always allow a

period of five minutes after power-off for the gyro rotor to come to restbefore you attempt to move the gyrocompass.


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Page 2 of 6 Issue 2.10 TSS (International) Ltd DPN 060079

CAUTION

During operation, the gyrocompass must remain level to within 45. Ifit experiences til t greater than 45 in any direction, it wil l topple.

Never apply a tilt of more than 45 with the gyro rotor spinning or

during the gyrocompass initialisation procedure. Note that the gyrorotor continues to spin for approximately five minutes after you power-off the System.

CAUTION

If you install the gyrocompass in an enclosed space, make certain thereis suff icient ventilation and circulation of free air to allow effectivecooling.

CAUTION

Remove power from the gyrocompass before making any connectionsto external equipment.

CAUTION

You wil l void the warranty if you operate the gyrocompass outside theenvironmental conditions detailed in Section 4 and in BS EN 60945.

CAUTION

The Merid ian Surveyor should be suppl ied with power from an SELVsource as defined in IEC/EN 60950. The power supply source should beswitched and protected by a suitable circuit breaker.

CAUTION

Perform these simple maintenance instructions only if you have theski lls and experience required, and only when necessary. Inappropriatetampering with the internal controls and components of the gyrocom-pass can lead to damage or serious performance degradation.

NEVER open the gyrocompass cover or make any adjustments insidethe gyrocompass unless you are entirely conf ident in your actions.


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Contents


CONTENTS

1 Introduction 111.1 System Description 13

1.1.1 Gyrocompass 13

1.1.2 Remote Control Unit 141.1.3 Auxiliary Inputs 151.1.4 Heading Outputs 15

1.2 Principle of Operation 152 Installation 212.1 Unpacking and Inspection 222.2 Physical and Electrical Installation 23

2.2.1 Selecting a location 232.2.2 Gyrocompass installation 242.2.3 External Remote Control Unit 2102.2.4 Set the Gyrocompass DIP Switches 211

2.3 Alignment 2152.4 Final Gyrocompass Installation Tests 2162.5 Installation Drawings 2173 Operating Instructions 313.1 Control Features 323.2 Initial Power-on 333.3 Operating Procedure 34

3.3.1 Latitude correction 343.3.2 Speed correction 353.3.3 DG operating mode 35

3.4 Error Modes 363.4.1 Loss of GPS 363.4.2 Loss of speed log 363.4.3 Gyrocompass system warnings and failures 37

3.5 Operating Considerations 393.5.1 General Operating Considerations 393.5.2 Corrections for Speed and Latitude 393.5.3 Operating at Extremes of Latitudes 393.5.4 Operating Considerations for Vessel Dynamics 310

4 Technical Data 414.1 Specifications 41

4.1.1 Power Requirements 414.1.2 Performance (definitions as in ISO 8728) 414.1.3 Compensation 414.1.4 Environment 414.1.5 Signal Inputs 424.1.6 Signal outputs 424.1.7 Dimensionsand Weight 424.1.8 Listener load requirement 434.1.9 Talker drive capability 434.1.10 Standards 43

4.2 Data Formats 444.2.1 IEC 61162 Serial Data Formats General information 45


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4.2.2 Inputs 464.2.2.1 IEC 61162 input signals 464.2.2.2 Pulsed input 410

4.2.3 Outputs 4114.2.3.1 IEC 61162 output signals 411

4.2.4 IEC 61162 sentence with Checksum 4154.2.5 Other Output Formats 416

4.2.5.1 Robertson serial output 4164.2.5.2 SG Brown ASCII serial output 4174.2.5.3 Synchro Output 4184.2.5.4 Resolver Output 4184.2.5.5 Stepper S-Code 4184.2.5.6 Rate of Turn 4185 Maintenance 515.1 Built-in Test Equipment 52

5.1.1 Azimuth Drift Adjustment 53

5.1.2 Azimuth Bias Adjustment 535.2 Test Connector 545.3 Diagnostic Output Sentence 56


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TABLE OF AMENDMENTS

Old Issue New Issue Date Details

- 1.0 27 Jun 2000 New release.

1.0 1.0A 12 Dec 2000 Corrected identification of Azimuth Bias potentiometer and

other details. Include DIP switch default settings.

1.0A 1.0B 1 Mar 2001 Amendments to J8 configuration. Amendments to NMEA

format definitions.

1.0B 1.0C 23 Apr 2001 Add notification to avoid product modifications.

1.0C 2.0 Aug 2002 Substantial amendments to reflect product enhancements

2.0 2.1 Sept 2002 Completion of enhancement features including compliance with

IEC 61162

2.1 2.2 Jan 2003 Minor amendments and description of Diagnostic Output

Sentence.

2.2 2.3 Feb 2003 Modification to specifications and addition of Appendix B to

demonstrate Certificate of Type Approval.

2.3 2.4 Mar 2003 Minor amendments to a display warning and a note referring to

confirming software release.

2.4 2.5 July 2003 Note added regarding modification kit available for alternative

orientations when attempting correct speed compensation.

2.5 2.6 August 2003 Minor amendments to specifications throughout

2.6 2.7 March 2004 Amendments to alarms warning / failure designation

2.7 2.8 June 2006 Revised Company Logo

2.8 2.9 December 2006 Removed references to B929033 and 929033.

2.9 2.10 January 2008 Replaced manual setting of DG Mode on distribution board with

Alarm Acknowledgement functionality. This enables

compatibility with the Compass Changeover System.


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1 Introduct ion

DPN 060079 TSS (International) Ltd Issue 2.10 Section 1 Page 1 of 6

1 INTRODUCTIONThe Meridian Surveyor is a master heading reference instrument that applies thecharacteristics of a dynamically tuned gyroscope and the effects of gravity and earthrotation to provide a true north reference.

The Meridian Surveyor specification makes the System ideal for installation andoperation on board vessels of almost any size and in a wide range of applications.

Among the standard features of the Meridian Surveyor are:

A short settling time

Operation from a 24V DC electrical supply

This Manual is an important part of the Meridian Surveyor. It describes the Systemand contains full installation and operating instructions. You should retain the Manualwith the System for use by personnel who will install and operate it.

Installation and operation of the Meridian Surveyor are not complex tasks. However,you should spend time to familiarise yourself with the contents of this Manual beforeyou start to install or use the System. Time spent in identifying the task sequence nowwill ensure your System is operational in the minimum of time.

WARNINGS

Where appropriate, this Manual includes important safety informationhighlighted as WARNING and CAUTION instructions. You must obeythese instructions:

WARNING instructions alert you to a potential risk of death or in jury tousers of the System.

CAUTION instructions alert you to the potential risk of damage to theSystem.

For your convenience, the Contents section includes copies of all theWARNING and CAUTION instruct ions included in this Manual.

Throughout this Manual all measurements conform to the SI standard of units unless

otherwise indicated.

IEC61162 and NMEA0183 are equivalent standards for interfacing marine electronicdevices. Throughout this Manual IEC61162 is used.


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Section 1 Page 2 of 6 Issue 2.10 TSS (International) Ltd DPN 060079

For your convenience, this Manual includes several sections, each of which describesspecific features of the Meridian Surveyor:

You should read sections 1 and 2 before you attempt to install the System:

Section 1 contains introductory notes and describes those items supplied as

standard.Section 2 describes how to select a suitable location for the gyrocompass. This

section includes full instructions to install the System and connect it toexternal equipment.

You should read sections 3 and 4 before you use the System:

Section 3 describes how to operate the Meridian Surveyor.

Section 4 includes the System specifications and descriptions of the data formats.

You should read sections 5 if you suspect a fault on the System:

Section 5 describes how to use the internal 60-way test connector and explains howto conduct simple adjustments with the gyrocompass housing removed.

This Manual also contains the fol lowing appendices:

Appendix A explains how a gyroscope can be made north seeking for use in agyrocompass.

Appendix B contains copies of Type Approval Certificates.

CAUTION

You wil l void the warranty if you make any modi fications to this

equipment without prior permission from TSS (International) Ltd.

DO NOT modify this equipment in any way without obtainingpermission from TSS (International) Ltd.


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1 Introduct ion


1.1 SYSTEM DESCRIPTION

The Meridian Surveyor comprises two sub-assemblies:

The gyrocompass housing

The Remote Control Unit (RCU)

Figure 11 shows the combined gyrocompass housing with the RCU included as anintegral unit.

The Meridian Surveyor applies dynamic tuning to settle automatically to the meridian.Due to the physical principles of a north-seeking gyrocompass, achievable accuracydepends on the operating latitude and the vessel dynamics. To optimise itsperformance, the Meridian Surveyor uses information supplied by externalequipment, for example a GPS receiver and a speed log, to apply latitude and speedcorrections.

Refer to Appendix A for a simplified explanation of the gyrocompass theory ofoperation.

1.1.1 GYROCOMPASS

Figure 11: Gyrocompass housing

with integral RCU

Figure 11 shows thegyrocompass housing, whichcontains the following items:

True north seeking dynamicallytuned precision gyroscope andgimbal suspension assembly.

Power supply board.

Digital and analogue controlboards.

RFI filter and distribution board.

It is a relatively simple operation toinstall the gyrocompass and you

should be able to accomplish thisquickly without the need forspecialised personnel orequipment. However, note that thegyrocompass weighs 15.5kg andyou must take due care when youlift and move it.

The care that you take when you align the gyrocompass housing with the surveyedfore-aft axis of the vessel will have a direct impact on the accuracy of headingmeasurements delivered by the System. Since the Meridian Surveyor is an ideal

source of heading information for use by other systems on board, such as radars andsatellite communication antennas, the accuracy of its heading measurements will


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have a wide impact throughout the vessel. You should therefore take care when youinstall and align the gyrocompass. Refer to Section 2 for full instructions to install,connect and align the Meridian Surveyor.

The only component available for user servicing is a 3.15A line fuse inside thegyrocompass housing. In case of failure, refer to Section 5 for instructions forinstructions on fault diagnosis and maintenance.

1.1.2 REMOTE CONTROL UNIT

Figure 12: Remote Control Unit

The Remote Control Unit (RCU) provides all the functions and indicators necessary to

control and operate the Meridian Surveyor.

The four-character LED can show a range of information:

Heading in Degrees. 000.0 to 359.9

Latitude. 80S to 80N

Latitude Source

Speed in Knots. 00 to 90

Speed Source

Alarms and Status information

Separate LED indicators show Power On and Compass Ready conditions

Refer to Section 3 for instructions to operate the Meridian Surveyor.


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1 Introduct ion


1.1.3 AUXILIARY INPUTS

Auxiliary inputs may be used for the Meridian Surveyor to apply latitude and speedcorrections.

Ideally, the Meridian Surveyor should accept latitude and speed information from

external sources such as a GPS receiver or a speed log. However, you may supplythis information manually if external sources are not available. The advantage ofusing GPS or a speed log to provide correction signals is that they allow automaticcorrections to be applied without operator intervention.

Section 2 includes instructions to connect and configure the external sources oflatitude and speed information.

Section 3 includes instructions to set the latitude and speed manually.

1.1.4 HEADING OUTPUTS

The Meridian Surveyor is a self-contained precision navigation instrument that iscapable of supplying heading reference information simultaneously to a wide range ofequipment on board the vessel. Throughout a typical vessel, applications that canuse information supplied by the Meridian Surveyor include:

Autopilot

Radars

GPS

Radio direction finder

Course plotter and recorder

Satellite communication systems

Satellite television

To support this wide range of equipment types, the Meridian Surveyor can supplyheading information simultaneously through multiple channels using any of thecommon transmission formats.

Refer to Section 4 for a description of the available output channels and their dataformats. Refer to Section 2 for details on how to interconnect to other equipment.

1.2 PRINCIPLEOF OPERATION

In the absence of external influences, a free-spinning gyroscope will try to maintain afixed orientation in space. The Meridian Surveyor exploits this property and usesgravity control and earth rotation to align the gyroscope spin axis with the meridian,i.e. the true north direction.

Refer to Appendix A for the general theory of gyrocompass operation


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2 Installation


2 INSTALLATIONTo obtain the best performance from the Meridian Surveyor you must take care whenyou install and connect it. This section includes all the information and instructionsyou will need to complete these tasks.

You should read this section carefully and understand the important instructions thatit contains before you begin to install or connect the equipment.

2.1 Unpacking and Inspection Page 2

Explains the inspection checks that you should perform as you unpack the MeridianSurveyor.

2.2 Physical and Electrical Installation Page 3

Choose a suitable location to install the Meridian Surveyor. Connect the system to anelectrical supply and to external equipment.

2.3 Alignment Page 15The care that you take as you align the Meridian Surveyor with the fore-aft datum onthe vessel will have a direct influence upon its accuracy.


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2.1 UNPACKINGAND INSPECTION

WARNING

The Meridian Surveyor weighs 15.5kg. To avoid personal in jury, takeproper precautions i f you li ft or move the equipment.

CAUTION

The Meridian Surveyor includes precision components and bearings.To avoid causing damage to any part of the System, handle all i temswith care.

Retain the original transit cases so that you can use them to t ransportthe system when necessary. You wi ll void the warranty i f you useimproper packing during transportation.

CAUTION

Severe damage to the Meridian Surveyor can occur if you move thegyrocompass while the rotor is still spinning without the servo systemin operation.

Note that the gyro rotor continues to spin for approximately fiveminutes after you power-off the system.

To avoid potential damage to the Meridian Surveyor, always allow aperiod of five minutes after power-off for the gyro rotor to come to restbefore you attempt to move the gyrocompass.

The Meridian Surveyor undergoes a full series of electrical and mechanical testsduring manufacture and before dispatch. The packing case has a special design toprotect the contents against shock during transit so that the equipment should arrivewithout damage or defect.

As soon as possible after you have received the system, check all items against theshipping documents. Inspect all sub-assemblies carefully to check for any damagethat may have occurred during transportation. If you see any damage file a claim withthe carrier and immediately notify TSS (International) Ltd.

To avoid loss or damage to any components of the system, store all sub-assembliessafely in the transit case until you need to install them. Obey the storage temperature

limits listed in Section 4.

Notify TSS (International) Ltd immediately if there are any components missing fromthe shipment.

The title page of this Manual lists the contact details for TSS (International) Ltd.


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2.2 PHYSICALAND ELECTRICAL INSTALLATION

2.2.1 SELECTINGALOCATION

There are certain guidelines that you should follow to install the Meridian Surveyorsuccessfully:

CAUTION

During operation, the gyrocompass must remain level to within 45. Ifit experiences til t greater than 45 in any direction, it wil l topple.

Never apply a tilt of more than 45 with the gyro rotor spinning orduring the gyrocompass initialisation procedure. Note that the gyrorotor continues to spin for approximately five minutes after you power-off the System.

The gyrocompass weighs 15.5kg. Choose a mounting location that is level, flatand sufficiently strong to support the unit without flexing or experiencing extremevibration. The mounting location can be open, as on a chart table, or enclosedwithin a cabinet.

CAUTION

If you install the gyrocompass in an enclosed space, make certain thereis suff icient ventilation and circulation of free air to allow effectivecooling.

Choose a location that protects the Meridian Surveyor from damage.

Do not install or operate the Meridian Surveyor where the ambient temperaturecould fall below 0C or rise above +45C, or where rapid changes of temperaturecan occur.

Do not install the Meridian Surveyor close to strong mechanical or electrical noisesources, or in a location susceptible to vibration or shock.

Allow a minimum distance of 0.4m between the gyrocompass housing and anystandard magnetic compasses.

Choose a location that allows convenient access to install, connect and servicethe Meridian Surveyor. Refer to Figure 24 for clearance dimensions.


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2.2.2 GYROCOMPASSINSTALLATION

You must align the Meridian Surveyor so that its fore-aft axis is parallelto the fore-aft datum on the vessel. Any misalignment between thegyrocompass housing and the vessel wi ll have a direct effect on theaccuracy of heading measurements delivered by the system.

To install the Meridian Surveyor you will need the following tools:

Screwdriver 5.5mm 150mm

Screwdriver 3mm 75mm

Nut spinner 5.5mm

8.5mm drill

3 x M8 bolts of suitable length complete with washers and nuts

Combination spanner 10mm

Adjustable spanner opening to at least 33mm

Suitable cables for the installation as indicated in Table 21.

There should be no need to remove the gyrocompass cover during installation. TheConnector Panel allows you to make all necessary power and signal connections tothe Meridian Surveyor. There is a removable panel on the top of the gyrocompassthat allows access to the internal DIP switches and a 60-way test connector.

1. During installation you must align the Meridian Surveyor so that its fore-aft axis isparallel with the fore-aft datum on the vessel. It is not necessary for thegyrocompass to be on the vessel centre line. There are alignment marks on thebase of the Meridian Surveyor to help you achieve the correct alignment.

2. Three elongated securing holes machined into the gyrocompass base allow you tomake fine adjustments to alignment after installation. With the gyrocompasspositioned accurately, mark the supporting surface with the centre positions forthe three securing holes. Refer to Figures 23 and 24 for dimensions.

3. Remove the gyrocompass and drill three 8.5mm diameter holes, using the marksyou have just made on the supporting surface as hole centres. Deburr the holes

and remove any swarf.

Table 21: Suitable cable t ypes

Purpose Suitable cable

Power supply 7/0.5mm (1.5mm2) HOFR sheathed to BS6883

Synchro heading output

Resolver heading output

Stepper S-code output

7/0.4mm (1.0mm2

) butyl or EP rubber insulated, CSPsheathed, wire braided and CSP oversheathed.

Serial data heading output

Serial data speed input

Serial data latitude input

1/0.85mm (0.6mm2) twisted pair, butyl or EP rubber insulated,

CSP sheathed, wire braided and CSP oversheathed.


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4. Reposition the gyrocompass and align it to the fore-aft datum. Use three M8 boltswith washers and nuts to secure the gyrocompass in position.

5. Connect a 24V electrical supply (acceptable range 18V to 36V DC) to the MeridianSurveyor at J 1, the three-pin power inlet on the Connector Panel. Figure21shows the Connector Panel.

To prevent any possibil ity o f damage to the gyrocompass while thevessel is moving it is recommended that an uninterruptable electricalsupply is used to power the Meridian Surveyor.

6. Connect the ships safety ground to the earthing stud adjacent to the electricalsupply inlet J 1.

7. Make all necessary signal connections to the Meridian Surveyor at the ConnectorPanel. To maintain EMC compliance you should terminate all wire braiding on thecables at the D-type back shells.

Figure 21: Gyrocompass connector panel

CAUTION

Remove power from the gyrocompass before making any connectionsto external equipment.

Before removing the cover or the RCU

unit, remove the gland plate and

disconnect the RCU cable (TB1/17-22)

from the distribution board.

CAUTION

Serial No.

3.15AF

Fuse24VDC

Watford, England.Mfg. Date

Build Standard No.

Compass Min. Safe Dist. m

Gland plate release screws

Cover plate release screws


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Table 22: J1 Power supply input p in details

Pin Description

1 Protective ground

2 +24V DC

3 0V

Table 23: Ports on the connector panel

Port Function Style

J1 Electrical supply inlet AMP-style square flange mounting

J2 Synchro/S-type outputs See Table24 15-pin D-type socket

J3 Rate of turn output See Table25 9-pin D-type socket

J4 Serial data (Channel 1) outputs See Table26 25-pin D-type socket



J7 Serial data inputs See Table29 25-pin D-type plug

J8 Log input See Table210 9-pin D-type socket

J9 Status and alarm outputs See Table211 15-pin D-type plug



Table 24: J2 - Synchro/S-type outputs pin details

Pin Description

1 Protective ground

2 0V Synchro/Resolver

3 26V Synchro R1

4 S3 Synchro Resolver

5 S2 Synchro Resolver

6 S1 Synchro

8 0V

12 L3

13 L2

14 L1

15 5V


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2 Installation


Table 25: J3 - Rate of turn output pin details

Pin Description

1 Protective ground

2 Rate of turn3 ROT 0V

4 RCU 24V IN (+)

5 RCU 24V IN ()

6 RCU IN () (N/C)

7 RCU ON/OFF

8 RCU RS422A (S+)

9 RCU RS422B (S-)

Table 26: J4 - Serial data (Channel 1) outputs p in details

Pin Description

1 Protective ground

3 RS232 Signal

7 RS232 Return

11 20mA Signal

12 20mA Return

18 RS422 (B)

19 RS422 (A)


Pin Description

1 Protective ground

3 RS232 Signal

7 RS232 Return

11 20mA Signal

12 20mA Return

18 RS422 (B)

19 RS422 (A)


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Pin Description

1 Protective ground

3 RS232 Signal7 RS232 Return

11 20mA Signal

12 20mA Return

18 RS422 (B)

19 RS422 (A)

Table 29: J7 - Serial data inputs pin details

Pin Description

1 Protective ground

2 GPS RS232 Signal

7 GPS RS232 Return

14 Log RS422 Return (B)

15 Log RS422 Signal (A)

16 Log RS232 Return

17 Log RS232 Signal

18 GPS RS422 Signal (B)

19 GPS RS422 Return (A)

Table 210: J8 - Log inputs pin details

Pin Description

1 LOG (TTL) 0V

2 LOG (TTL) Signal

4 Protective ground

5 LOG (contact closure) Signal

6 LOG (contact closure)

8 LOG OK 0V

9 LOG OK Signal


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Table 211: J9 - Status and Alarm outputs pin details

Pin Description

3 Gyro Ready relay (open when not ready, closes when ready)

4 Gyro Ready relay CC5 Gyro Ready relay (closed when not ready, opens when ready)

6 Fail relay (normally closed, opens on failure)

7 Fail relay CC

8 Fail relay (normally open, closes on failure)

11 Alarm Acknowledge (0V)

12 Alarm Acknowledge ACK

13 Gyro Ready Return

14 Gyro Ready TTL

Table 212: J10 - Serial data (Channel 2) output s pin details

Pin Description

1 Protective ground

3 RS232 Signal

7 RS232 Return

11 20mA Signal

12 20mA Return

18 RS422 (B)

19 RS422 (A)

Table 213: J11 - Serial data (Channel 2) outputs pin details

Pin Description

1 Protective ground

3 RS232 Signal

7 RS232 Return

11 20mA Signal

12 20mA Return

18 RS422 (B)

19 RS422 (A)


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Section 2 Page 10 of 20Issue 2.10 TSS (International) Ltd DPN 060079

2.2.3 EXTERNAL REMOTE CONTROL UNIT

The standard Meridian Surveyor has the Remote Control Unit (RCU) mountedintegrally and available for immediate operation.

There may be applications where you prefer to install the RCU at some distance from

the gyrocompass unit. A mounting kit, part number 929190, is available to use inthese circumstances. The kit includes the following items:

RCU housing

Mounting bracket

Blanking plate for the gyrocompass housing

There is no need to remove the gyrocompass cover to install the RCU externally:

1. Release and remove the four M3 screws at the corners of the RCU that secure itto the gyrocompass housing.

2. Lift the RCU away from the gyrocompass housing as far as its cable will allow.

3. Reach inside the gyrocompass housing and disconnect the RCU cable at TB1 onthe Distribution Board.

4. Lift the RCU away from the gyrocompass.

The cable run between the Gyrocompass and the RCU must not exceed100 metres.

5. Use the bracket with the mounting kit to fix the RCU to a desk or to a bulkhead.

You may also flush mount the RCU in a panel. Choose a suitable location tomount the RCU:

The mounting surface can be vertical or horizontal according to requirements.

Avoid installing the RCU where it might experience severe shock or vibration.

Choose a location for the RCU that allows a clear view of the display in allconditions.

6. Use the two star knobs supplied to fit the RCU into the mounting bracket. Tilt theunit to a convenient viewing and operating angle and then lock it in place bytightening both star knobs.

7. Supply and fit a cable to connect the RCU to J 3 pins 4 to 9 on the ConnectorPanel (refer to Table 25 for pin details of this port). The cable must have threescreened twisted pairs and should not exceed 100 metres in length.

8. Fit the blanking plate to fill the gap left in the cover by the RCU.


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2.2.4 SETTHE GYROCOMPASS DIP SWITCHES

1 There is a removable panel on top of the gyrocompass that allows access to thetwo internal DIP switches (shown in Figure 22) without the need to remove themain gyrocompass cover. Release and remove the three securing screws to lift offthe panel.

2. Refer to Tables 214, 215, 216and 217to set the DIP switches for the specificrequirements of your installation. Do not adjust the settings of other presetcontrols inside the gyrocompass.

3. Refit the access panel to the top of the gyrocompass cover.

Figure 22: Location of DIP switches


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Table 214: SW1 DIP switch settings Poles 1 to 6 (Channel 1 configuration)

SW2 DIP switch settings Poles 1 to 6 (Channel 2 configuration)

Factory default settings appear in bold and are marked with an asterisk in this table

The DIP switch settings described in this table are only applicable togyrocompasses fitted with software versions BPR 0115 (Main) and BPR

0114 (RCU) or later. If necessary, you can view the software versions ofthe main and the RCU processors by pressing both the Up and theDown selection buttons simultaneously. The display will togglebetween indications of the main processor software version (withprefix 'M') and the RCU software (with prefix 'R'). The display willcontinue to toggle for several seconds after you release the buttonsand will then return to the heading indication.

6 5 4 3 2 1

Data Format Baud Rate Update Rate C-Sum Decimal Places ROT1= ON 0 = OFF

(as marked on swit ch)

1 1 1 1 1 1 IEC 61162 4800 1 Y 1 N

1 1 1 1 1 0 IEC 61162 4800 1 N 1 N

1 1 1 1 0 1 IEC 61162 4800 10 Y 1 N

1 1 1 1 0 0 IEC 61162 4800 10 N 1 N

1 1 1 0 1 1 IEC 61162 4800 1 Y 2 N

1 1 1 0 1 0 IEC 61162 4800 1 N 2 N

1 1 1 0 0 1 IEC 61162 4800 10 Y 2 N

1 1 1 0 0 0 IEC 61162 4800 10 N 2 N

1 1 0 1 1 1 IEC 61162 4800 1 Y 1 Y

1 1 0 1 1 0 IEC 61162 4800 1 N 1 Y

1 1 0 1 0 1 IEC 61162 4800 10 Y 1 Y

1 1 0 1 0 0 IEC 61162 4800 10 N 1 Y

1 1 0 0 1 1 IEC 61162 4800 1 Y 2 Y

1 1 0 0 1 0 IEC 61162 4800 1 N 2 Y

1 1 0 0 0 1 IEC 61162 4800 10 Y 2 Y

1 1 0 0 0 0 IEC 61162 4800 10 N 2 Y

1 0 1 1 1 1 IEC 61162 9600 1 Y 1 N

1 0 1 1 1 0 IEC 61162 9600 1 N 1 N

1 0 1 1 0 1 IEC 61162 9600 10 Y 1 N

1 0 1 1 0 0 IEC 61162 9600 10 N 1 N

1 0 1 0 1 1 IEC 61162 9600 1 Y 2 N

1 0 1 0 1 0 IEC 61162 9600 1 N 2 N

1 0 1 0 0 1 IEC 61162 9600 10 Y 2 N


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2 Installation


1 0 1 0 0 0 IEC 61162 9600 10 N 2 N

1 0 0 1 1 1 IEC 61162 9600 1 Y 1 Y

1 0 0 1 1 0 IEC 61162 9600 1 N 1 Y

1 0 0 1 0 1 IEC 61162 9600 10 Y 1 Y

1 0 0 1 0 0 IEC 61162 9600 10 N 1 Y

1 0 0 0 1 1 IEC 61162 9600 1 Y 2 Y

1 0 0 0 1 0 IEC 61162 9600 1 N 2 Y

1 0 0 0 0 1 IEC 61162 9600 10 Y 2 Y

1 0 0 0 0 0 IEC 61162 9600 10 N 2 Y

0 1 1 1 1 1 IEC 61162 38400 1 Y 1 N

0 1 1 1 1 0 IEC 61162 38400 1 N 1 N

0 1 1 1 0 1 IEC 61162 38400 10 Y 1 N

0 1 1 1 0 0 IEC 61162 38400 10 N 1 N

0 1 1 0 1 1 IEC 61162 38400 50 Y 1 N

0 1 1 0 1 0 IEC 61162 38400 50 N 1 N

0 1 1 0 0 1 IEC 61162 38400 1 Y 2 N

0 1 1 0 0 0 IEC 61162 38400 1 N 2 N

0 1 0 1 1 1 IEC 61162 38400 10 Y 2 N

0 1 0 1 1 0 IEC 61162 38400 10 N 2 N

0 1 0 1 0 1 IEC 61162 38400 50 Y 2 N

0 1 0 1 0 0 IEC 61162 38400 50 N 2 N

0 1 0 0 1 1 IEC 61162 38400 1 Y 1 Y

0 1 0 0 1 0 IEC 61162 38400 1 N 1 Y

0 1 0 0 0 1 IEC 61162 38400 10 Y 1 Y

0 1 0 0 0 0 IEC 61162 38400 10 N 1 Y

0 0 1 1 1 1 IEC 61162 38400 50 Y 1 Y

0 0 1 1 1 0 IEC 61162 38400 50 N 1 Y

0 0 1 1 0 1 IEC 61162 38400 1 Y 2 Y

0 0 1 1 0 0 IEC 61162 38400 1 N 2 Y

0 0 1 0 1 1 IEC 61162 38400 10 Y 2 Y

0 0 1 0 1 0 IEC 61162 38400 10 N 2 Y

6 5 4 3 2 1




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Meridian Surveyor


Table 216: SW1 DIP switch settings Pole 8 (Vessel Dynamic s)

Factory default settings appear in bold and are marked with an asterisk in this table.

0 0 1 0 0 1 IEC 61162 38400 50 Y 2 Y

0 0 1 0 0 0 IEC 61162 38400 50 N 2 Y

0 0 0 1 1 1 Robertson 9600 50 N/A 1 N/A

0 0 0 1 1 0 SGB(10th) 4800 10 N/A 1 N/A

0 0 0 1 0 1 SGB(6th) 4800 10 N/A 1 N/A

0 0 0 1 0 0 SGB(10th) 9600 10 N/A 1 N/A

0 0 0 0 1 1 SGB(6th) 9600 10 N/A 1 N/A

0 0 0 0 1 0 SGB(10th) 38400 10 N/A 1 N/A

0 0 0 0 0 1 SGB(6th) 38400 10 N/A 1 N/A

0 0 0 0 0 0 All Data* 4800* 1* Y* 1* Y*

Note: 1. For full IEC 61162 compliance, a checksum must be transmitted.

Table 215: SW1 DIP switch sett ings Pole 7 (Analogue ROT Scaling)

Factory default settings appear in bold and are marked with an asterisk in this table.

7

Analogue ROT Scaling1=ON 0=OFF

(as marked on switch )

1 +/- 60 deg/min = +/- 10V

0* +/- 20 deg/s = +/-10V*

8

Vessel Dynamics1=ON 0=OFF


1For HSC applications. Refer to 3.5.4

(for gyrocompasses with serial numbers later than 3500)

0* Standard Control Mode*

6 5 4 3 2 1




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2 Installation


Table 217: SW2 DIP switch sett ings Poles 7 and 8 (Speed log input t ype)

Factory default settings appear in bold and are marked with an asterisk in this table

2.3 ALIGNMENTIt is important to align the gyrocompass to the vessel accurately. Any misalignmentbetween the housing and the vessel will appear directly as a fixed error in headingmeasurements. Because measurements from the Meridian Surveyor are available foruse by diverse systems around the vessel, any misalignment between thegyrocompass and the fore-aft datum might have a significant impact in many otherareas of application.

There are several methods you may use to align the gyrocompass to the vessel fore-aft datum:

Align the gyrocompass to the fore-aft datum using a known reference line, such asa surveyed bulkhead or frame member. The marks on the gyrocompass baseplate are precision indicators of the gyrocompass alignment orientation.

To achieve correct speed compensation, the gyrocompass must beorientated so that the connector plate faces the forward end of thevessel. Note that modification kits are available for alternativegyrocompass orientations.

Use the services of a marine surveyor to align the gyrocompass precisely with thefore-aft datum.

Remove any residual misalignment by making minuscule adjustments to thegyrocompass mounting plate. When you have achieved perfect alignment, tighten thesecuring bolts fully to lock the gyrocompass in position.

7 8

Speed Log Input Type1=ON 0=OFF


1 1 100 pulses/nm

0 1 200 pulses/nm

1 0 400 pulses/nm

0* 0* LOG Serial Data*


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Meridian Surveyor


2.4 FINAL GYROCOMPASS INSTALLATION TESTS

After you have installed the gyrocompass and power supplies are available to it,perform the following installation tests:

1. Power-on the gyrocompass by following the instructions in sub-section3.2. Wait

for three hours before you perform the following tests.

2. Check the vessel heading against a known reference mark on a chart. Typicallythis could be the alongside position of the fitting-out dock. Alternatively, accuratelysurvey an object at least five kilometres ahead of the vessel using the fore-aft lineas a datum.

3. Check the displayed gyrocompass heading at intervals to make certain it isconsistent with the surveyed vessel heading.

4. If there is an error larger than 0.5, re-check the vessel fore-aft datum to confirmthat it is correct.

5. Check that all the repeaters are accurately aligned with the gyrocompass headingand make certain they maintain their alignment at all times while the gyrocompassis powered-on.


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2 Installation


2.5 INSTALLATION DRAWINGS

Figure 23: Gyrocompass installation Sheet 1

30330 3

40

170

110

160

SE 130140

120

150

70

90

80

100

E

NE 60

40

50

250

230

190 180200

S21

022

0

SW240

N

NW

320

270

260

W

280

300

290

310

20100350

24VDCFuse

3.15AF

CAUTION

BeforeremovingthecoverortheRCUunit,removetheglandplateand

disconnecttheRCUcable(TB1/17-22)

fromthedistributionboard.


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Meridian Surveyor


Figure 24: Gyrocompass installation Sheet 2

30330 3

40

170

110

160

SE 130140

120

150

70

9 0

80

100

E

NE60

40

50

250

230

190 180200

S21

022

0

SW240

N

NW320

270

260

W

280

300

290

310

20100350

BeforeremovingthecoverortheRCU

unit,removetheglandplateand

disconnecttheRCUcable(TB1/17-22)

fromthedistributionboard.

CAUTION

3.15AFFuse 24VDC


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2 Installation


Figure 25: RCU installation Table mount


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Meridian Surveyor


Figure 26: RCU installation Flush mount


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3 Operating Instructions


3 OPERATING INSTRUCTIONS

This section explains how to power-on and configure the Meridian Surveyor afterinstallation. Refer to Section 4 for an explanation of the data formats relevant to theSystem.

3.1 Control Features Page 2The RCU provides all the controls you will need to operate the Meridian Surveyor. Italso includes a four-character display panel that shows the heading indication, anyalarm messages and error codes.

3.2 Initial Power-on Page 3

Explains how to power-on the Meridian Surveyor after installation and describes theinitialisation sequence.

3.3 Operating Procedure Page 4

Explains how to select the latitude and speed correction sources, and how to set the

latitude and speed manually if necessary.

3.4 Error Modes Page 6

Identifies the system error modes. Use these indicators to identify a possible faultcondition.

3.5 Operating Considerations Page 9

Includes general advice for operating the Meridian Surveyor on a vessel and on highspeed craft.


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Meridian Surveyor


3.1 CONTROL FEATURES

Figure 31: RCU front panel features

The RCU front panel includes all the operator controls for the Meridian Surveyor:

Table 31: RCU Control and Indicator functions

Control Function

Power switch. Recessed to prevent accidental operation.

Selection Up. Press to increase display brightness.

Selection Down. Press to decrease display brightness

Latitude selection button. Press to display current Latitude source and correction value.

Use in conjunction with the Selection Up and Selection Down buttons to pre-set Latitude source

and correction value.

Speed Selection. Press to display current Speed source and correction value. Use in conjunction

with the Selection Up and Selection Down buttons to pre-set Speed source and correction value.

Alarm . Press to silence the audible alarm.

012.3 Four digit alphanumeric display.Note: The display can show additional information by alternating the display contents at 0.5Hz.

This is indicated throughout the manual as, for example, L52N+ SGPS

Power lamp (red) Indicates that the Meridian Surveyor is switched on when 24V DC nominal power isconnected.

Ready lamp

(green)

Indicates that the Meridian Surveyor has settled and a True Heading is available.

Table 32: RCU displ ay formats

Format Function

Heading

0123.4

0123.4 + DG

0123.4 + DG_L

Heading Only

Heading with DG mode set at the RCU

Heading with DG mode set by latitude greater than 80 deg


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3.2 INITIAL POWER-ON

The Meridian Surveyor starting cycle is fully automatic after power is applied. Forcorrect operation Latitude and Speed correction must be applied.

1. Check that there is a nominal 24V DC electrical supply available to thegyrocompass. The acceptable supply range is 18V to 36V DC.

To ensure continuous operation, the power supply for this unit should have a200W power rating.

2. To start the Meridian Surveyor press the power switch on the RCU.

3. Check that the red Power lamp on the RCU illuminates. This lamp indicates onlythat the Meridian Surveyor is receiving power and does NOT indicate a settledcondition. The instrument illumination will be at maximum during the initialisationsequence. Even at its maximum setting, the instrument illumination may bedifficult to see in bright ambient lighting.

4. The RCU will activate the audible alarm for about 1 second. The display willindicate T.E.S.T. and the Ready lamp will be lit for about 10 seconds while thesystem performs a series of self-tests. After successful completion of the self-tests, the display will show the current Gyrocompass dial heading and the Readylamp will go off until the Gyrocompass has settled.

Initially the indicated heading could be inaccurate by as much as 180.The indicated heading should not be relied on unt il the Gyrocompasshas settled, indicated by an illuminated Ready lamp.

5. Set the source of latitude information by following the instructions in sub-section3.3.1.

6. Set the source of speed information by following the instructions in sub-section3.3.2.

Speed (by pressing the Speed button)

S_01 + S.MAN

S_01 + S.GPS

S_01 + S.LOG

S_01 + P.LOG

Speed value with Manual selected speed source

Speed value with GPS selected speed sourceSpeed value with LOG selected speed source (serial data input)

Speed value with LOG selected speed source and Pulse Log DIP switch set

(pulse input)

Latitude (by pressing the Latitude button)

L.52N + L.MAN

L.52S + L.MAN

L.52N + L.GPS

Latitude value in the Northern Hemisphere with Manual selected Latitude

source

Latitude value in the Southern Hemisphere with Manual selected Latitude

source

Latitude value with GPS selected Latitude source

Table 32: RCU displ ay formats

Format Function


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Meridian Surveyor


7. Use the Selection Up and Selection Down buttons to adjust the RCU illuminationlevel to a comfortable setting.

8. Wait for the gyrocompass to settle. This will occur automatically and will takeupwards of 24 minutes depending on initial heading offset and sea conditions. TheMeridian Surveyor signifies its settled condition by illuminating the green Ready

lamp.

9. If necessary, you can view the software versions of the main and the RCUprocessors by pressing both the Selection Up and the Selection Down buttonssimultaneously. The display will toggle between indications of the main processorsoftware version (with prefix M) and the RCU software (with prefix R). Thedisplay will continue to toggle for several seconds after you release the buttonsand will then return to the heading indication.

3.3 OPERATING PROCEDURE

The Meridian Surveyor will settle automatically after power-on, to provide a true north

reference. The system requires only latitude and speed correction, applied manuallyor from external sources, to perform to the specified accuracy.

Ideally, the Meridian Surveyor should accept latitude and speed information fromexternal sources such as a GPS receiver or a speed log, which allow the System toapply corrections automatically.

3.3.1 LATITUDECORRECTION

1. Press and hold the Latitude selection button.

2. Use the Selection Up and Selection Down buttons to set the local latitudemanually. The display will show the latitude in one-degree increments in the range80N to 80S, for example L70N

To select automatic latitude compensation from a GPS receiver, use the up ordown selection buttons to scroll beyond 80N or 80S until the display showsLGPS.

If there is no valid input available from a GPS receiver, the display willindicate a LGPS alarm after 30 seconds.

3. Release both buttons to set the latitude to the displayed value or to set thegyrocompass to use GPS as the source of automatic latitude correction. Thedisplay will indicate the latitude setting and latitude source for several seconds

and will then return to the normal heading display.If you input the operating latitude manually, remember to change thesetting when necessary. Note that, in medium lati tudes, a 10 error insetting the operating latitude will result in a compass error ofapproximately 0.5.


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3.3.2 SPEEDCORRECTION

1. Press and hold the Speed selection button.

2. Use the Selection Up and Selection Down buttons to set the speed manually inthe range zero to 90 knots.

To select automatic speed compensation from a GPS receiver or a speed log, usethe Selection Up button to scroll beyond 90 knots until the display shows SGPS orSLOG.

If there is no valid input available from a speed log or GPS receiver, thedisplay wi ll indicate a SLOG or SGPS alarm after 30 seconds.

3. Release both buttons to set the speed to the displayed value or to set thegyrocompass to use GPS or a speed log as the source of automatic speedcorrection. The display will indicate the speed setting and speed source forseveral seconds and will then return to the normal heading display.

If you input the vessel speed manually, remember to set the averagevessel speed and to change the setting when necessary. Return thesetting to zero on completion of the voyage. For a vessel steaming in anortherly direction, a 5-knot error in speed setting will generate an errorof approximately 0.5.

3.3.3 DG OPERATINGMODE

To select Directional Gyro (DG), use the Selection Up and Selection Down buttonsto scroll beyond 80N or 80S until the display shows DG.

In this mode you can use the Meridian Surveyor as a direction indicating instrument

all the way up to the poles. If the gyrocompass has settled on north immediately priorto entering the DG mode, it will continue to provide a useful indication of the northerlydirection for a period, but will not continue to seek north. The length of time that thedirection indication remains valid depends entirely on the gyro drift characteristics.

DG mode will be automatically enabled for latitudes settings greaterthan 80 applied from the GPS input.

The gyrocompass will not north seek while operating in the DG mode.


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Meridian Surveyor


3.4 ERROR MODES

The Meridian Surveyor has three possible Error modes:

1. Loss or corruption of GPS signal

2. Loss or corruption of speed log signal

3. Gyrocompass system warnings and failures

3.4.1 LOSSOF GPS

This failure mode can occur when you have selected GPS as the source of speed orlatitude information and the signal corrupts or becomes lost for a period of 30seconds. You can recognise this condition by the following indications:

The display shows S.GPS + FAIL for the loss of speed correction information.

The display shows L.GPS + FAIL for the loss of latitude correction information.

The audible alarm will sound.

Press the Alarm button to cancel the audible alarm.

1. The Gyrocompass will use the last valid speed and latitude values.

2. The RCU will continue to show the alarm message until a valid input signal is re-established or a different input source is selected.

3. If the valid input signal has not been established within a period of 30 minutes theaudible alarm will be enabled.

3.4.2 LOSSOFSPEEDLOGThis failure mode can occur when you have selected speed log as the source ofspeed information and the signal corrupts or becomes lost for a period of 30 seconds.You can recognise this condition by the following indications:

The display flashes SLOG + FAIL for the loss of selected serial data sourceinformation.

The display flashes PLOG + FAIL for the loss of pulsed selected sourceinformation.


Press the Alarm button to cancel the alarm.

1. The Gyrocompass will use the last valid speed value.

2. The RCU will continue to show the alarm message until a valid input signal is re-established or a different input source is selected.

If a valid input signal has not been established within a period of 30 minutes theaudible alarm will be enabled.


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3.4.3 GYROCOMPASSSYSTEMWARNINGSANDFAILURES

The Meridian Surveyor has a built-in system that monitors operation of thegyrocompass. The functions that this system checks are split into two categories.

Warning conditions

Failure conditions

A failure condit ion wi ll resul t in the Gyroscope power supply beingdisabled. Refer to the maintenance section 5 before activating thePower Supply.

Warning Conditions

If the gyrocompass detects a warning condition, it will use two methods to alert you:

The display shows + FAIL



The RCU will continue to show the alarm message until the fault condition has beenremoved. If the fault condition has not been removed within a period of 30 minutes theaudible alarm will be enabled. Refer to sub-section 5.1 which outlines some simple

checks that you can make to rectify these fault conditions. If necessary contact TSS(International) Ltd or an approved local service agent for assistance.

Table 33: Gyrocompass warning codes

RCU ScreenDefinition of warning code

dc + fail Internal DC power supply is outside operating limits

ac + fail Internal AC power supply is outside operating limits

rdc + fail Loss of internal timing signals

Temp + fail Over or under operating temperature range

rMT + fail Loss of serial communication link with the RCU


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Meridian Surveyor


Failure Conditions

If the Meridian Surveyor detects a failure condition, it will use six methods to alert you:

The display shows + FAIL


The Ready lamp will extinguish.

The Gyro Fail relay will activate.

Serial output will transmit empty sentences.

Stepper output will transmit an illegal code.


This failure is considered to be an unrecoverable fault condition, possibly due to acomponent failure.

To prevent damage to the Gyroscope the power supplies to it will be disabled.

The Gyrocompass wi ll be disabled until it has been reset by theoperator. Refer to the maintenance section 5 before activating thePower Switch.

Table 34: Gyrocompass failure code

RCU ScreenDefinition o f failure code

rot + Fail Rate of Turn exceeds 300o/s


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3.5 OPERATING CONSIDERATIONS

3.5.1 GENERAL OPERATING CONSIDERATIONS

You should leave the Meridian Surveyor running continuously. Power-off thesystem only during long periods of lay-up, for example during vessel dry-docking.

To power-off the Meridian Surveyor, press the Power button. The heading displaywill go blank and the front panel lamps will switch off. The gyro rotor will takeapproximately five minutes to come to rest.

If you intend to leave the system powered-off for an extended period, you shouldarrange to run the gyrocompass for a period of at least thirty minutes at intervalsof six months or less.

The Meridian Surveyor has full protection against interruption of its electricalsupply. It will re-start and align itself automatically on restoration of electricalpower. The heading indication will be accurate when the RCU Ready lamp is on.

Monitor the Meridian Surveyor performance regularly. When functioning correctly,and provided the correct Speed and Latitude compensations are applied, theheading error in latitudes up to 60 and for speeds up to 25 knots will normally beless than 0.75 regardless of the vessel manoeuvres.

Never move the gyrocompass with the gyro rotor spinning unless you leave theservos operational. Note that the gyro rotor continues to spin for a period ofapproximately five minutes after you power-off the gyrocompass.

3.5.2 CORRECTIONSFOR SPEEDAND LATITUDE

Gyrocompass operational accuracy depends, to a large extent, upon accuratecorrections for speed and latitude being applied.

Most users find that the facilities for the automatic application of speed andlatitude corrections, via signal inputs from GPS and/or ships log, are a convenientmethod of applying corrections.

However, users should be aware that if the input signal contains the wronginformation, then the wrong corrections will be applied. For instance, it has beennoted that some GPS installations, under certain circumstances, will output avalid signal with the speed and latitude fields set to all zeros indicating that thevessel is stationary on the equator.

An incorrect input of speed and/or latitude will cause the gyrocompass to indicatean incorrect heading and in the case of extreme errors could cause, in certaincircumstances, the gyrocompass to come out of the Ready mode.

3.5.3 OPERATINGAT EXTREMESOF LATITUDES

As latitude increases (north or south) the magnitude of the horizontal componentof the Earths rotation rate reduces in proportion to the cosine of latitude.Consequently, the effectiveness of the gyrocompasses north seeking actionreduces with increasing latitude.

At latitudes greater than 80o it is recommended that the gyrocompass be operatedin the DG (directional gyro) mode.

If correction for the effect of latitude on the vertical component of Earths rotation ismade manually via the RCU, then correction is available to 80o. Thereafter, the


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Meridian Surveyor


directional gyro mode should be manually selected. Errors in the indicatedheading will increase with time and increasing latitude above 80o to a maximum ofapproximately 0.25o /hour. To re-align the gyrocompass, operating latitude mustbe reduced below 80o and the gyrocompass mode of operation re-selected.

If correction for the effect of latitude on the vertical component of Earths rotation is

made automatically via a serial data input, then correction is available above 80oand directional gyro mode is automatically selected above this latitude. Thecompass will still be subject to small inherent drifts while operating in this mode.Reversion to the gyrocompass mode will be made automatically when the serial

data latitude input falls below 80o.

3.5.4 OPERATING CONSIDERATIONSFOR VESSEL DYNAMICS

The gyrocompass gravity control gives rise to errors whenever the gyrocompassaccelerates or decelerates along the north-south line, that is whenever thenortherly speed or course changes. These errors are caused by the inertia of thependulous element of the gyro, which produces a torque about the horizontal axis

and therefore a precession in azimuth. This effect, calledballistic deflection,causes an increase in error during acceleration.

The precession in tilt that arises from the damping component of gravity control iscalled ballistic tilt. The combined effects of ballistic tilt and ballistic deflectioncause the gyrocompass to tilt downwards. Because of the factors that guide thebehaviour of a damped gyroscope, the gyro spin axis will return to the settledposition by the normal anticlockwise spiral after the acceleration has ceased.

In the Meridian Surveyor, gravity control comes from an accelerometer(pendulum), which generates an electrical signal related to the tilt of the gyro spinaxis. This device has two important design features; it is heavily damped and the

range of output is restricted to a small angle.The use of accelerometer damping by the Meridian Surveyor is of primeimportance in the reduction of a particularly serious form of ballistic error calledinter cardinal rolling error. This type of error occurs most noticeably when thevessel steams on an inter cardinal heading while rolling simultaneously through asignificant angle.

If the gyrocompass is installed at some distance above the vessel centre of rollrotation, as is usually the case on commercial vessels, the resulting lateralacceleration components along the east-west and north-south axes of thegyrocompass combine to build an error in the northerly settle point.

If the effect persists for long enough, this error might become as large as severaldegrees. However, by damping the accelerometer using a time constant severaltimes larger than the vessel rolling period, inter cardinal rolling errors aresignificantly reduced.

Another form of ballistic error arises from north-south accelerations generated byvessel manoeuvres. Such accelerations can arise from changes in speed and/orcourse. By limiting the angular output of the accelerometer, the Meridian Surveyorreduces the error potential typically to less than one degree.

It is also possible to eliminate acceleration effects by temporarily operating the

compass in the DG (Directional Gyro) mode. In this mode gravity control is usedfor tilt corrections only, so that ballistic effects would cause negligible heading


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error during short-term acceleration periods. The DG mode can be selectedmanually from the control panel.

If the special gyro control mode for HSC is selected, the DG mode will be appliedautomatically in conditions of high accelerations.

This mode of control is recommended for High Speed Craft and othervessels which may be subjected to high accelerations induced by rapidchanges of speed or heading.

Under these conditions, operation in the standard control mode cancause automatic reversion to the settle mode and consequently largerdynamic heading errors .

The Meridian Surveyor complies with all requirements of IMO ResolutionA.821(19), Performance Standards for Gyrocompasses for High-Speed Craft.


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Meridian Surveyor



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4 Technical Data


4 TECHNICAL DATA4.1 SPECIFICATIONS

CAUTION

You wil l void the warranty if you operate the gyrocompass outside theenvironmental conditions detailed in Section 4 and in BS EN 60945.

4.1.1 POWER REQUIREMENTS

Voltage 24V DC (acceptable range 18V to 36V DC)

Power consumption 3A at power on, 1.2A continuous (The powersupply capacity should exceed 200W)

CAUTION

The Merid ian Surveyor should be suppl ied with power from an SELVsource as defined in IEC/EN 60950. The power supply source should beswitched and protected by a suitable circuit breaker.

To comply with the requirements of IMO Resolution A.821(19), PerformanceStandards for Gyrocompasses for High Speed Craft, power to the gyrocompassshould be delivered by an uninterruptable power supply.

4.1.2 PERFORMANCE (DEFINITIONSASIN ISO 8728)

Settle point error 0.1 sec latitudeStatic error 0.05 sec latitude RMS

Dynamic accuracy 0.2 sec latitude (Scorsby andIntercardinal motion tests)

Settle point repeatability 0.1 sec latitude

Follow up speed 200/s

Time to settle within 0.7 Less than 45 minutes with a 30 initialheading offset

4.1.3 COMPENSATION

Latitude compensation range 80N to 80S

Speed compensation range 0 to 90 knots

4.1.4 ENVIRONMENT

Operating environment EN 60945:1997 designated categoryweather protected

Operating temperature 0C to +45C (to ISO 8728)15C to +55C (with reduced accuracy)

Storage temperature 25C to +80C


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Meridian Surveyor


4.1.5 SIGNAL INPUTS

Latitude IEC 61162 message string via RS232 orRS422 from GPS

Speed Pulse or contact closure at 100, 200 or 400

per nautical mile from speed logIEC 61162 message string at 4800 baud viaRS232 or RS422 from speed log

Alarm Acknowledgement Voltage free alarm ACK contacts

4.1.6 SIGNALOUTPUTS

S-type heading 1 step-by-step, 6 steps per degree (TTL

level) update limited to 20o/s to preventrepeater misalignment

Synchro heading 1 26V 400Hz (11.8V maximum line-to-line),sector value 360

Analogue rate of turn 1 rate of turn 60/min (10V) or 20/s(10V)

Serial data outputs 5 RS2325 RS4225 20mA digital current loop

Serial data formats IEC 61162, Robertson, SGB ASCII at 1Hz,10Hz or 50Hz.

Status/alarm 5V TTL power/gyro failureVoltage free power/gyro failure contacts5V TTL system readyVoltage free system ready contacts

4.1.7 DIMENSIONSAND WEIGHT

Dimensions 344mm (H) 267mm (W) 440mm (D)

Weight 15.5kg

RCU size (when mounted externally) 96mm (H) 192mm (W) 108mm (D)

RCU weight 0.75 kg

Disposal

WARNING

Do not dispose of by fire or compacting, as toxic fumes, dust or liquidsmay be released.

Units contain electrical and electronic components which should be disposed of inaccordance with current waste disposal practices.

Units may be returned to the manufacturer for safe disposal.


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4 Technical Data


4.1.8 LISTENERLOADREQUIREMENT

The gyrocompass presents a listener load of 1.6mA typical at 2V or 3.5mA typical at5V to all serial data input signals.

Figure 41: Listener input circu it

4.1.9 TALKERDRIVECAPABILITY

The gyrocompass has a talker drive capability of 150mA to ground.

Derived from 26C31 line drivers.

4.1.10 STANDARDS

The Meridian Surveyor is designed to meet the requirements of the following:

IMO Resolution A.424 (XI), Performance Standards for Gyrocompasses

IMO Resolution A.821 (19), Performance Standards for Gyrocompasses for HighSpeed Craft

BS EN 60945 (2002), General Requirements - Methods of testing and required

test results BS EN ISO 8728:1999, Shipbuilding Marine Gyrocompasses

BS 6217:1981, Graphical Symbols for use on Electrical Equipment

CE marking

Electromagnetic Compatibility (EMC) Directive

The Marine Equipment Directive 96/98/EC

IEC 61162-1:2000(E) Maritime navigation and radio communication equipmentand systems - Digital interfaces. Note that IEC 61162-1:2000(E) is closely alignedwith NMEA 0183 version 2.30

USCG, United States Coast Guard Type Approval


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Meridian Surveyor


4.2 DATA FORMATS

Set the DIP switches according to your specific input and output requirements. You

will find the instructions to do this in sub-section 2.2.4.

Inputs Refer to sub-section 4.2.2

Acceptable input formats: Latitude information using serial IEC 61162 GNS, RMC, GLL or GGA sentences. If

more than one of these formats is available, the Meridian Surveyor makes itsselection in the stated preference order. Refer to Figures43, 44, 45 and 46respectively for a description of these formats.

Datum reference using IEC 61162 DTM sentence. The latitude offset is not usedto correct the gyroscope latitude information, however the DTM sentence is re-transmitted.

Speed information using serial IEC 61162 VBW, RMC, VTG or VHW sentences.

The sentences can contain speed information using knots and/or km/h. TheMeridian Surveyor will use the speed in knots if available, in preference to speedin km/h. If more than one of these formats is available, the Meridian Surveyormakes its selection in the stated preference order. Refer to Figures48, 44, 49and 410 respectively for a description of these formats.

If an RMC sentence is used it must contain both speed and latitude information.

TTL-compatible pulsed speed input with a TTL-level signal or contact closure.

Outputs Refer to sub-section 4.2.3

Serial output formats:

The Meridian Surveyor transmits selected information through RS232 and RS422serial lines using the IEC 61162 format. The serial transmission rate can be either4800, 9600 or 38400 baud, with updates occurring at 1Hz, 10Hz or 50Hz as definedby the setting of the DIP switches.

Other output formats:

Synchro Heading Output

Stepper S-code Heading Output

Rate of turn using a bipolar analogue voltage in the range 10V

The following sub-sections describe each of the formats supported by the MeridianSurveyor.


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4 Technical Data


4.2.1 IEC 61162 SERIAL DATA FORMATS GENERALINFORMATION

The Meridian Surveyor accepts and transmits asynchronous serial data using 8 databits, one stop bit and no parity through RS232 and RS422 transmit-only lines. Thedata bits occur in each packet with the least significant bit first. The most significant bitof the 8-bit character will always be zero.

Figure 42: Serial data format

All data is interpreted as ASCII characters that form IEC 61162 sentences split intoindividual fields. All fields, including null fields, are separated by commas.

The IEC 61162 format requires a checksum if included, the checksum occurs as anadditional field immediately before the carriage return line-feed characters. It consistsof an asterisk (*) followed by a checksum derived by exclusive OR-ing the eight databits of each valid character preceding the asterisk, but excluding the $ symbol, in thesentence. The absolute value of the checksum is transmitted in ASCII charactersrepresenting the value in HEX. For circumstances where the Meridian Surveyorretransmits serial data using the same IEC 61162 sentence format supplied by anexternal source, it will recalculate any checksum and insert the new value into theoutput sentence.

IEC 61162 sentences are usually transmitted once per second, however you can set

a DIP switch to select a transmission update rate of either 1, 10 or 50 per second. Theoutputs are grouped into two channels that can be set independently. The All Dataoutput option of heading, latitude, speed, datum, rate of turn and time sentences willalways be transmitted at 1Hz.


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4.2.2 INPUTS

4.2.2.1 IEC 61162 INPUTSIGNALS

The Meridian Surveyor will accept sentences in both IEC 61162-1:2000(E) and NMEAversion 2.1 data formats.

In the following descriptions of input sentences, the Meridian Surveyor uses the datafields marked XXX in the IEC 61162 sentence. The system does not use the fieldsmarked ??? and their descriptions are included here for completeness only. Thegyrocompass will recognise the arriving sentence format and will extract the requireddata from it automatically.

GPS Interface (see Table 2-9 for connection details)

The Meridian Surveyor can accept speed, latitude, date and time inputs at the GPSinterface in IEC 61162 format using GNS, RMC, GLL, GGA, VTG, VHW and ZDAsentences.

Figure 43: IEC 61162 GNS input sentence structure

Figure 44: IEC 61162 RMC input sentence structure

$??GNS,??????.??,XXXX.XX,X,?????.??,?,X--X,??,?.?,?.?, [CRLF]?.?,?.?,?.?*??

Ta

lker

iden

tifier

(any

charac

ters

)

Mnemon

icfo

rG

NSSfix

da

ta

UTCo

fp

os

ition

Nort

h/Sou

th

La

titude

(ddmm

.mm

)

Long

titude

Carr

iage

return

Line

-fee

dc

harac

ters

Start

charac

ter

Eas

t/Wes

t

Differen

tia

lre

ference

station

ID

Chec

ksum

fie

ld

Age

of

differen

tia

ld

ata

Geo

ida

ls

epera

tion

,m

An

tenna

altitu

de

,m

,re

:mean

-sea

-leve

l(g

eo

id)

HDOP

Tota

ln

um

ber

of

sa

tellites

inu

se

,0

-99

Mo

de

Indica

tor

$??RMC,??????.??,X,XXXX.XX,X,?????.??,?,X.X,?.?,??????,?.?,?,X[CRLF]

Ta

lker

iden

tifier

(an

yc

harac

ters

)

Mnemon

icfo

rR

ecommen

ded

Min

GPSda

ta

UTCo

fp

os

ition

(hhmmss

.ss

)

La

titud

e(d

dmm

.mm

Mnemon

icfo

rN

ort

ho

rS

ou

th

Status

,A

=v

alid

,V

=Nav.

Rec

eiver

warn

ing

Long

itu

de

(dddmm

.mm

)

Mnemon

icfor

Eas

to

rW

es

t

Magne

ticvaria

tion

indicator

eas

to

rW

es

t

Groun

ds

pee

dink

no

ts

Magne

tic

variat

ion

ind

egrees

Course

over

grou

nd

ind

egrees

Da

teo

ffi

x

Carr

iage

return

Line

-fe

ed

charac

ters

S

tart

charac

ter

M

ode

Indica

tor


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4 Technical Data


Figure 45: IEC 61162 GLL input sentence structure

Figure 46: IEC 61162 GGA input sentence structure

Figure 47: IEC 61162 DTM input sentence structure

$??GLL,XXXX.XX,X,?????.??,?,??????.??,X,X[CRLF]

Ta

lker

iden

tifier

(any

charac

ters

)

Mnemon

icfo

rg

eograp

hical

La

ta

nd

Lon

La

titude

(ddmm

.mm

)

Long

itu

de(d

ddmm

.mm

)

Mnemon

icfo

rNo

rth

or

Sou

th

Mnemon

icfo

rE

as

to

rW

es

t

Carr

iage

return

Line

-fee

dc

harac

ters

Sta

rtc

harac

ter

UTCo

fp

os

ition(

hhmmss

.ss

)

Status

Mo

de

Indica

tor

$??GGA,??????.??,XXXX.XX,X,?????.??,?,X,??,?.?,?.?,?,?.?,?,?.?,????[CRLF]

Ta

lker

iden

tifier

(any

charac

ters

)

Mnemon

icfo

rG

PSfix

da

ta

UTCo

fp

os

ition

(hhmmss

.ss

)

La

titude

(ddmm

.mm

Mnemon

icfo

rN

ort

ho

rS

ou

th

Long

itu

de

(dddmm

.mm

)

Mnemon

icfo

rE

as

to

rW

es

t

GPSqua

lity

indica

tor

Num

ber

of

sa

tellites

inu

se

(00

-1

2)

Horizon

tal

dilution

of

prec

ision

Antenna

altitu

de

relative

tom

ean

sea

leve

l

Mnemon

icfo

rm

etres

Mnemon

icfo

rm

etres

Geo

ida

ls

epara

tion

Age

of

differen

tia

lG

PSda

ta

Differen

tia

lre

ference

station

(0000

-1

023)

Carr

iage

return

Line

-fee

dc

harac

ters

Start

charac

ter

$??DTM,???,?,?.?,?,?.?,?,?.?,???*hh[CRLF]

Ta

lker

iden

tifier

Mnemon

icfo

rD

atumre

ference

Locald

atumsu

bdivision

co

de

La

titude

offse

t

Loca

ld

atum

Re

ference

da

tum

Nort

h/Sou

th

Chec

ksum

fie

ld

Carr

iage

retur

nL

ine

-fee

dc

harac

ters

Start

charac

ter

Long

itu

de

offse

t

Eas

t/Wes

t

Altitu

de

offse

t,m


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Meridian Surveyor


Figure 48: IEC 61162 VBW input sentence structure

Figure 49: IEC 61162 VTG input sentence structure

Figure 410: IEC 61162 VHW input sentence structure

$??VBW,?.?,?.?,?,X.X,?.?,X,?.?,?,?.?,?*hh[CRLF]

Ta

lker

iden

tifier

(any

charac

ters

)

Mnemon

icfo

rD

ua

lg

roun

d/w

ater

spee

d

Long

itu

dina

lw

aterspee

d,k

no

ts

Status:

wa

ter

spee

d,A

=v

alid

,V

=n

ot

va

lid

Transverse

wa

terspee

d,k

no

ts

Long

itu

dina

lg

roun

dspee

d,k

no

ts

Carr

iage

return

Line

-feed

charac

ters

Start

charac

ter

Transverse

groun

dspee

d,k

no

ts

Status:

stern

groun

ds

pee

d,A

=v

alid

,V

=n

ot

va

lid

Che

cksum

fie

ld

Status:

groun

ds

pee

d,A

=v

alid

,V

=n

ot

va

lid

Stern

transverse

wa

terspee

d,k

no

ts

Status:

stern

wa

ter

spee

d,A

=v

alid

,V

=n

ot

va

lid

Stern

transverse

groun

dspee

d,k

no

ts

$??VTG,?.?,?,?.?,?,X.X,X,XX.X,X,X[CRLF]

Talker

iden

tifier

(any

charac

ters

)

Mnemonic

for

groun

dc

ourse

an

ds

pee

d

Mnemon

icfo

rT

rue

hea

ding

Mn

emon

icfo

rM

agne

tic

hea

ding

Course

ind

egrees

an

dte

nths

Mnemon

icfo

rk

no

ts

Spee

dink

no

ts

Spee

dink

m/h

Mnemon

icfo

rk

m/h

Carr

iag

ere

turn

Line

-fee

dc

harac

ters

Start

charac

ter

Course

ind

egrees

an

dte

nths

Mo

de

indica

tor


55/78

4 Technical Data


Figure 411: IEC 61162 ZDA input sentence structure

Log Interface (see Table 23 or connection details)

The Meridian Surveyor can accept speed inputs at the Log interface in IEC 61162

format using VBW, VTG and VHW sentences only.Figure 412: IEC 61162 VBW input sentence structure

Figure 413: IEC 61162 VTG input sentence st ruc ture

$??ZDA,XXXXXX.XX,XX,XX,XXXX,??,??[CRLF]

Ta

lker

iden

tifier

(any

charac

ters

)

Mnemon

icfo

rTim

ea

nd

Da

te

Day

of

mont

h(0

1to3

1)

Mon

tho

fyea

r(0

1to1

2)

UTC(h

hmmss

.ss

)

Loca

lz

one

hours

(00

to

13)

Year

Loca

lz

one

minu

tes

(00

to+

59)

Carr

iage

return

Line

-feed

charac

ters

Sta

rtc

harac

ter

$??VBW,?.?,?.?,?,X.X,?.?,X,?.?,?,?.?,?*hh[CRLF]

Talker

iden

tifier

(any

charac

ters

)

Mnemon

icfor

Dua

lg

roun

d/wa

ter

spee

d

Long

itu

dina

lw

ater

spee

d,k

no

ts

Status:

wa

ters

pee

d,A

=v

alid

,V

=n

ot

va

lid

Tra

nsverse

wa

ter

spee

d,k

no

ts

Longi

tudina

lg

roun

ds

pee

d,k

no

ts

Carr

iage

return

Line

-fee

dc

harac

ters

Start

charac

ter

Transverse

groun

ds

pee

d,k

no

ts

Status:

stern

groun

ds

pee

d,A

=v

alid

,V

=n

ot

va

lid

Chec

ksum

fie

ld

Status:

groun

ds

pee

d,A

=v

alid

,V

=n

ot

va

lid

Stern

tra

nsverse

wa

ter

spee

d,k

no

ts

Status:

stern

wa

ters

pee

d,A

=v

alid

,V

=n

ot

va

lid

Stern

tran

sverse

groun

ds

pee

d,k

no

ts

$??VTG,?.?,?,?.?,?,X.X,X,XX.X,X,X[CRLF]

Ta

lker

iden

tifier

(any

charac

ters

)

Mnemon

icfo

rg

roun

dc

ourse

an

dspee

d

Mnemon

icfo

rT

rue

hea

ding

Mnemon

icfo

rM

agne

tic

hea

ding

Course

ind

egrees

an

dte

nths

Mnemon

icfo

rk

no

ts

Spee

dink

no

ts

Spee

din

km

/h

Mnemon

icfork

m/h

Carr

iage

return

Line

-fee

dc

harac

ters

Start

charac

ter

Course

ind

egrees

an

dten

ths

Mo

de

indica

tor


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Meridian Surveyor


Figure 414: IEC 61162 VHW input sentence structure

4.2.2.2 PULSEDINPUTThe Meridian Surveyor can accept a speed input as a series of pulses or contactclosures occurring at a frequency of 100, 200 or 400 per nautical mile as selected bya DIP switch. Refer to Table217. The gyrocompass determines the vessel speed byreference against the microprocessor timing circuits. The speed pulses do not needto have a particular mark/space ratio, although they should be TTL-level. Contactclosures should be of good quality and electrically floating.


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4 Technical Data


4.2.3 OUTPUTS

4.2.3.1 IEC 61162 OUTPUTSIGNALS

The Meridian Surveyor can output data through RS232 and RS422 transmit-onlyserial

060079 Meridian Surveyor

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