ISUAL Instrument Software S. Geller. CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 2 Topics Presented Software Functions SOH Telemetry.

ISUAL Instrument Software

S. Geller

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller

2

Topics Presented

• Software Functions• SOH Telemetry• Command Processing• Science Telemetry• Operational Modes• Software Tasks


3

Terminology

• AEP - Associated Electronics Package• DCM - Data Compression Module• PVCF - Pseudo Virtual Channel Frame

– transmission unit for sending science packets to the ground

• SOH - Status of Health– Housekeeping data


4

Instrument Software Functions

• Receive and execute Commands• Generate Status telemetry (SOH)• Instrument Control and Readout• Management of Readout Data

– Pass data to DCM for compression

– Generate science telemetry packets

– Make packets into PVCFs; store in spacecraft buffer.

– Transfer PVCF data to Satellite


5

DPU processor

• 8085 processor• Programmed in assembly Language• Some code is heritage from IMAGE/FUV• Instrument control software developed by UCB


6

SOH Telemetry

• Command Echoes and other real-time status is sent out the Command Status channel

• Some of the short status packets may be directed to:– SOH channel

– Science telemetry channel

– Both

– Neither


7

ApID=71C Analog Monitors Packetbyte-offset element size no. elements

-6 1 1 100 0 1 111-5 1 1 Ap ID LSB's = 00000110-4 1 1 11xxxxxx = source seq cnt MSB's-3 1 1 Source Sequence Count LSB's-2 1 1 Packet Length MSB-1 1 1 Packet Length LSB0 10 1 Secondary Header (Time when Housekeeping was sampled)

10 1 1 Mass Mem +5 Current11 1 1 Mass Mem +5 Voltage12 1 1 DSP +5 Current13 1 1 DSP +5 Voltage14 1 1 Array Photometer +5 Current15 1 1 Array Photometer +5 Voltage 16 1 1 Imager TEC +5 Current17 1 1 Imager TEC +5 Voltage18 1 1 Camera Interface +5 Current

Analog Monitors Packet


8

ApID=0x71D Digital Housekeeping Packet

byte-offset element size no. elements

-6 1 1 100 0 1 111-5 1 1 Ap ID LSB's = 00000110-4 1 1 11xxxxxx = source seq cnt MSB's-3 1 1 Source Sequence Count LSB's-2 1 1 Packet Length MSB-1 1 1 Packet Length LSB0 10 1 Secondary Header (Time when packed was generated)

10 1 1 Mode: 0=Standby, 1=Aurora, 2=Continuous,3=Burst, 4=Dayside11 1 1 1= Camera Active12 1 1 1= Spectrophotometer active13 1 1 1= Array Photometer active14 1 1 which photometer was selected for trigger15 2 1 trigger level17 1 1 which sun-sensors were selected18 1 1 day(1)/night(0) sensed19 4 1 N PVCFs sent 23 4 1 N Sprites/Lightning Events27 2 1 N MMCBs needing compression

Digital Housekeeping Packet


9

Command Processing

• Commands are received from the satellite as CCSDS command packets.

• Commands may be received at any time.• Some commands are executed immediately• Most commands have a Time Tag for later execution


10

Command Packet Definition

• Document 8564-X7 defines command packets


11

Example of Command Definition

I_RUN Load and Run DPU Program from EEPROMbyte-offset element size no. elements

-6 1 1 000 1 1 111 Primary Header: Version, Type, SecHdFlag, hi 3 bits of ApID-5 1 1 Ap ID LSB's 0x02=Immediate, 0x03=Time-Tagged-4 1 1 11xxxxxx = source seq cnt MSB's-3 1 1 Source Sequence Count LSB's-2 1 1 Packet Length MSB-1 1 1 Packet Length LSB0 10 1 Secondary Header -- time when (time-tagged) command is to be executed

10 1 1 OpCode=0x0111 1 1 sequence number12 1 1 program code (1..7)13 1 1 filler14 1 1 checksum (covering offsset15 1 1 TLR Trailer - 0xAA

Total length of Packet Data Field in bytes Overall length of packet (including primary header)

I_PWR_ON Turn a Power Service Onbyte-offset element size no. elements

-6 1 1 000 1 1 111 Primary Header: Version, Type, SecHdFlag, hi 3 bits of ApID-5 1 1 Ap ID LSB's 0x02=Immediate, 0x03=Time-Tagged-4 1 1 11xxxxxx = source seq cnt MSB's-3 1 1 Source Sequence Count LSB's-2 1 1 Packet Length MSB-1 1 1 Packet Length LSB0 10 1 Secondary Header -- time when (time-tagged) command is to be executed

10 1 1 OpCode=0x0211 1 1 sequence number12 1 1 Power Service13 1 1 filler14 1 1 checksum15 1 1 Trailer - 0xAA

Total length of Packet Data Field in bytes: 16 Overall length of packet (including primary header): 22


12

Time-Tagged Commands

• Stored in Time-Tagged List in DPU memory• Instrument software “background loop” continuously

checks command times against current UT• After execution, time-tagged are erased from

memory.


13

Command Groups

• Commands may be assigned a group number, and stored in the Time-Tagged List

• A single command will cause all commands in a group to be executed

• Group commands use the time-tag for order.


14

Group Command Procedures

• Group commands are not erased after execution; the group may be used again and again to execute common procedures.

• Groups may be erased or replaced by specific commands.


15

Example Command Procedure

• ; Clear Statistics and Faults

• /I_CLEAR_STATS

• /I_CLEAR_FAULTS

• ; Patch in readout buffer sizes

• /I_PATCH4 BANK=0 ADDR=CAM_RO_NBYTES DATA=X'00705566'

• /I_PATCH4 BANK=0 ADDR=SPH_RO_NBYTES DATA=X'00705566'

• /I_PATCH4 BANK=0 ADDR=APH_RO_NBYTES DATA=X'00705566'

• ; Patch in relative number of MMCBs per event

• /I_PATCH2 BANK=0 ADDR=N_CAM_MMCBS DATA=X'0070'

• /I_PATCH2 BANK=0 ADDR=N_SPH_MMCBS DATA=X'0070'

• /I_PATCH2 BANK=0 ADDR=N_APH_MMCBS DATA=X'0070'


16


• ;Set Filter

• /I_FILTER_SET ID=1

• ;Setup Camera

• /I_SPRITE_SETUP ID=NFRAMES VAL=123

• /I_SPRITE_SETUP ID=EXPOSURE VAL=123

• /I_SPRITE_SETUP ID=INTERVAL VAL=123

• /I_SPRITE_SETUP ID=NPOST VAL=123

• ;Setup SPH and APH too ...


17


• ;Turn on Mass Memory power

• /I_MM_ON ; Turn on Mass Memory

• /I_DELAY SECONDS=1 ; wait an extra second

• ;Allocate Mass Memory Control Blocks

• /I_MMCB_FORMAT ; format the MMCBs and readouts

• /I_DELAY SECONDS=1

• ;Allocate TM area

• ;for building packets, PVCFs and 64 Megabit "files".

• /I_TM_FORMAT ; format the PCVF buffers; start TM


18


• ;Turn on DCM

• /I_DCM_ON

• ;DCM shows "busy" until it completes its internal checks


•

• ; It's not convenient to check ground telemetry

• ; when running a time-tagged procedure,

• ; so we test the telemetry within the DPU's SOH array

• /I_VERIFY_SOH_BYTE OFFSET=DCM_Status MIN=2 MAX=2

• ; This "SCIENCE" Proc is executed as part of a command group.

• ; If test fails, remainder of command group is ignored

• ; and a Spacecraft Alert packet is generated.


19


• ;Copy DSP program from EEPROM to MM

• /I_DCM_PLB PLB=1 ; Copy PLB from EEPROM to MM

• ;Issue CDI commands

• /I_DCM_XMT OP= DATA=

• ;tell DCM where in MM it can get its initial MMCB and DSP program

• /I_DCM_START


• /I_VERIFY_SOH_BYTE OFFSET=DCM_Status MIN=1 MAX=1


20


• ;Turn on HV and other Science Power services

• /I_PWR_ON SERVICE=1




• ;Set mode; Start science data taking

• /I_SPRITE_CONT ; continuous mode

• ; Verify that Continuous Mode got started

• /I_DELAY=5

• /I_VERIFY_SOH_BYTE OFFSET=10 MIN=2 MAX=2


21

Data Compression

• All compression is done by the DCM• DPU allocates Mass Memory and supplies work for

the DCM


22

Telemetry Generation

• Telemetry products are generated as CCSDS source packets

• Packets are broken up into PVCFs and accumulated in memory until a 64 megabit Block is filled

• Block is transferred to spacecraft as a series of PVCF transmissions


23

Sprite Event Raw

readout Compressed Data

Science Products

---Instruments--- --Mass memory--------------- --Telemetry--

Science Data Flow

Camera frames

Spectrometer sample arrays


24

Operational Modes

• Standby• Data-Taking

– Sprite Continuous/Burst

– Aurora

• Dayside Data Processing


25

Standby Mode

• No Science Data taken• All science power services off• Command processing active• Status (SOH) telemetry generated• Mass Memory and DCM may or may not be turned

on.


26

Power-On Status

• At ISUAL Power-on,status is Standby Mode, plus...

• Mass Memory is off, DCM is off• Time-tagged command list is empty• PVCF storage is empty


27

Data-Taking Mode : Aurora

• Camera takes fixed-exposure at regular intervals; various filters set

• Photometer Data sampled at regular intervals and averaged


28

Data-Taking Mode : Sprite

• Data taking synchronized with a Sprite Event. DPU gets an interrupt and notes the time.

• When a camera readout is complete, DPU stamps the time and passes the data on for compression and science telemetry.

• Same for Photometers.


29

Dayside Data Processing

• No Data Taking• Data Compression from accumulated nightside raw

data• Telemetry Generation.• Command Processing

Note: at any time, a SAFE command will shut off all HV and switch to Standby Mode.


30

Software TasksSoftware Tasks

• A task is an independent code thread with its own stack.

• A task which is waiting for something will execute ‘call task'; this transfers control to the next task in a list of tasks.


31

Non-Preemptive multi-tasking

• ISUAL Flight Software uses a non-preemptive multi-tasking system. A task switch happens only when a task executes a 'call task'.

• Interrupt service routines do not change the current task, but an interrupt service routine may change the state of something which will cause the current task to do a 'call task'.


32

Tasks in ISUAL

• Background loop• SOH task - Generates housekeeping• Supply task - recycles readout memory• DCM task - manages compression• TM task - telemetry Packet Generator• SC task - send PVCFs to Spacecraft


33

Background Loop Task

• Command Processing– Receive Commands

– Execute commands from time-tagged list


34

O p er a te C M D _ I NS ta te M ac h in e

C o m m an dP ac k et

As s em b led ?

T P AP ac k et?

M B R R ep lyp ack et ?

Im m ed iateE x ecu te

C o m m an d ?

T im e-T aggedC o m m an d ?E c h o as

I n v a lid

E c h o as Q u eu ed .S to r e in

T im e- T ag g ed L is t

E x ec u te .E c h o as ex ec u ted .

S e t f lag :"M BR R ep ly

r ec e iv ed ".

C o p y toBr ac k ett in g

T P A p air

T r y to ex ec u te c o m m an d sf r o m th e T im e- T ag g ed lis t

N

Y

Y

N

Y

N

Y

N

YN

B a c k g ro u n d L o o p T a s k


35

SOH Task

• Generate Event Log packets• Generate Echo packets• Read Analog Monitors• Generate Analog Monitor and Digital Housekeeping

packets


36

E c h o esS to r ed ?

S en d E c h o P ac k et

R ead M o n ito r sS en d M o n ito r P ac k et

S en d S O H P ac k et

W ait T im eI n ter v a l

An y th in g inE v en t

Q u eu e?

S en d E v en t P ac k et

S O H T as k


37

Supply Task

• If an instrument readout is complete:– Mark the MMCB “ready for compression”

– Put MMCB on DCM queue

– Get another MMCB for that instrument

– Command a new readout address


38

M a rk M M C BR e a dy for C om pre s s ion

P ut M M C B onD C M que ue

S upply T a s k W a it fo r I n s tru m e n tR e a do u t C o m ple te

G e t a nothe r M M C BS e t ne w R /O a ddrs

Supply Task


39

DCM Task

• Get up to 16 MMCBs from DCM queue• Store in Mass Memory• Signal DCM to do compression• After compression, move MMCBs to TLM queue


40

Bu s y ?

N

YT im eo u t?

Y

N

D C MF au lt

M M C B L is tw as L o ad ed ?

Un lo ad C o m p r es s edD ata ; g en er a te T M

D C M Q ue ueh a s da t a ?

W r ite u p to 1 6 M M C Bsto M as s M em o r y

Y

N

S en d 2 C D I s tos e t ad d r es s o f

M M C B lis t

Ac tiv a te AT N

Bu s y ? T im e o ut ? D C M F a ultD eac tiv a te

AT NY

NY

D C M T a s k

N

N

Y


41

TM Task

• Wait for MMCB on TM queue• Generate Header Packet• Generate multiple data packets• Release MMCB to supply queue appropriate to

instrument


42

TM Task

G en er a teS c ien c e Head er p ac k e t

G en er a te m u ltip led a ta p ac k e ts

R eleas eM M C B

to S u p p lyQ u eu e

T M T a s k W a it fo r M M C B fro mTM qu e u e


43

SC Task

• Wait for SC buffer to fill• Send MBR message to spacecraft• Wait for reply command• Send PVCFs


44

R eq u es t f o rBu f f erF lu s h ?

S en d M BR p ac k et tos p ac ec r af t

W ait f o r r ep ly f ro m s p ac ec r af t

S en d P VC F s

S p ac ec r af tBu f f er f u llo f P VC F s ?

S C T as k

Y

N

N

Y

ISUAL Instrument Software S. Geller. CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 2 Topics Presented Software Functions SOH Telemetry.

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