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

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

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 5 DPU processor 8085 processor Programmed in assembly Language Some code is heritage from IMAGE/FUV Instrument control software developed by UCB

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 7 Analog Monitors Packet

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 8 Digital Housekeeping Packet

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 10 Command Packet Definition Document 8564-X7 defines command packets

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 11 Example of Command Definition

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

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

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 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' ' /I_PATCH4 BANK=0 ADDR=SPH_RO_NBYTES DATA=X' ' /I_PATCH4 BANK=0 ADDR=APH_RO_NBYTES DATA=X' ' ; 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'

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 16 Example Command Procedure ;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...

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 17 Example Command Procedure ;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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 18 Example Command Procedure ;Turn on DCM /I_DCM_ON ;DCM shows "busy" until it completes its internal checks /I_DELAY SECONDS=5 ; 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.

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 19 Example Command Procedure ;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_DELAY SECONDS=2 /I_VERIFY_SOH_BYTE OFFSET=DCM_Status MIN=1 MAX=1

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 20 Example Command Procedure ;Turn on HV and other Science Power services /I_PWR_ON SERVICE=1 /I_PWR_ON SERVICE=2 /I_PWR_ON SERVICE=3 /I_PWR_ON SERVICE=4 ;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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 21 Data Compression All compression is done by the DCM DPU allocates Mass Memory and supplies work for the DCM

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 23 Sprite Event Raw readout Compressed Data Science Products ---Instruments-----Mass memory Telemetry-- Science Data Flow Camera frames Spectrometer sample arrays

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 24 Operational Modes Standby Data-Taking –Sprite Continuous/Burst –Aurora Dayside Data Processing

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

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 27 Data-Taking Mode : Aurora Camera takes fixed-exposure at regular intervals; various filters set Photometer Data sampled at regular intervals and averaged

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

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 30 Software 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.

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

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 33 Background Loop Task Command Processing –Receive Commands –Execute commands from time-tagged list

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 34

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 35 SOH Task Generate Event Log packets Generate Echo packets Read Analog Monitors Generate Analog Monitor and Digital Housekeeping packets

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 36

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 38 Supply Task

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

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 40

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 41 TM Task Wait for MMCB on TM queue Generate Header Packet Generate multiple data packets Release MMCB to supply queue appropriate to instrument

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 42 TM Task

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 43 SC Task Wait for SC buffer to fill Send MBR message to spacecraft Wait for reply command Send PVCFs

CDR July, 2001NCKU UCB Tohoku ISUAL Instrument Software S. Geller 44