Types of Data Written to the Solid State Recorder

Related Pages

Physics Event Datagrams

FSW defines a "science data" APID space from 928 to 1023 for data written to the science data partition on the Spacecraft's Solid State Recorder, though not all telemetry in this range contains the types of physics or calibration data one might normally consider science data.

Various FSW applications and subsystems produce and transmit high volumes of data: the LAT Configuration (LATC) package can be used to dump the current instrument configuration as a series of telemetry packets; the LAT Computer Manager (LCM) can be configured to dump low-level software message traffic passed by the MSG utility; the onboard EEPROM filesystem manager (LFS) can be commanded to dump the contents of files of any size into telemetry.

The resulting data cannot be transmitted to the ground in a single contact and must therefore be stored in the science data partition of the SSR for later retrieval. Thus, science data APIDs are assigned to this information for purposes of routing it to temporary storage.

Product Science Data Tlm APID Summary Description Delivered Volume
SIU physics event data 955 (0x3BB)

Each science data telemetry packet with this APID contains multiple physics event data records in LAT Science Format (LSF), up to a maximum packet size of 4 Kbytes. The structure of the data is indicated by internal LSF headers.

Note: Though the SIU can be configured to participate in round-robin event data processing along with the EPUs, it is generally NOT configured this way, acting instead as a controller and coordinator for the EPUs.

In VC8; per SSR read Total volume per observation is variable. Event data is assembled into blocks of user-configurable maximum size, parceled into CCSDS packets of up to 4 Kbytes each. Assuming blocks are configured with a 64 Kbyte maximum size, the data is written to the SSR in up to 16 CCSDS packets.
EPU0 event data 956 (0x3BC) See above. See above. See above.
EPU1 event data 957 (0x3BD) See above. See above. See above.
EPU2 event data 958 (0x3BE) See above. See above. See above.
SIU EMP data (ACD rate counters) 985 (0x3D9) Each science data telemetry packet with this APID contains ACD rate counter data , formatted as datagrams in a special variant of the LAT Science Format. In VC8; per SSR read. Total volume per observation is variable.
EPU0 EMP data (ACD rate counters) 986 (0x3DA) See above. See above. See above.
EPU1 EMP data (ACD rate counters) 987 (0x3DB) See above. See above. See above.
EPU2 EMP data (ACD rate counters) 988 (0x3DC) See above. See above. See above.
SIU LCB and LATp Statistics 990 (0x3DE) Over a user-specified time period, FSW collects statistics kept by the LAT Communications Board driver on execution of the driver ISR routine, on transactions over the LATp command/response fabric, and on traffic on all protocols of the event data fabric; bundles these statistics into datagrams. The datagrams can also contain EBM receive and transmit statistics for the various LATp nodes (SIU, EPU, GEM, AEM, TEM, SSR). TBS. TBS.
EPU0 LCB and LATp Statistics 991 (0x3DF) See above. LCB driver statistics on EPU0. See above. See above.
EPU1 LCB and LATp Statistics 992 (0x3E0) See above. LCB driver statistics on EPU1. See above. See above.
EPU2 LCB and LATp Statistics 993 (0x3E1) See above. LCB driver statistics on EPU2. See above. See above.
Spacecraft ATTITUDE, ANCILLARY, TIMETONE messages (Magic 7 copy) 1020 (0x3FC) All Spacecraft ATTITUDE, ANCILLARY, and TIMETONE message packets (known collectively as the "Magic 7" packets) can be copied to the SSR. In VC8; per SSR read Once SIU FSW reaches Application Mode, Magic 7 packets are copied to SSR continuously as received from Spacecraft: 5 Hz for ATTITUDE, 1 Hz for TIMETONE, 1 Hz for ANCILLARY.
Charge injection calibration data 965 (0x3C5) Data sets collected from charge injection of the ACD, CAL, or TKR. VC8; Per SSR read CAL total size 4.6 Mbytes TKR total 13 Mbytes ACD 0.3 Mbytes
SIU memory dumps to SSR 980 (0x3D4) This telemetry contains words of data read from CPU memory. VC8; Per SSR read Variable depending on amount of memory dumped.
EPU0 memory dumps to SSR 981 (0x3D5) This telemetry contains words of data read from CPU memory. VC8; Per SSR read Variable depending on amount of memory dumped.
EPU1 memory dumps to SSR 982 (0x3D6) This telemetry contains words of data read from CPU memory. VC8; Per SSR read Variable depending on amount of memory dumped.
EPU2 memory dumps to SSR 983 (0x3D7) This telemetry contains words of data read from CPU memory. VC8; Per SSR read Variable depending on amount of memory dumped.
SIU file dump to SSR 975 (0x3CF) This telemetry contains contents of selected files stored in SIU0 EEPROM. VC8; Per SSR read Variable depending on amount of file data dumped.
EPU0 file dump to SSR 976 (0x3D0) This telemetry contains contents of selected files stored in EPU0 EEPROM. VC8; Per SSR read Variable depending on amount of file data dumped.
EPU1 file dump to SSR 977 (0x3D1) This telemetry contains contents of selected files stored in EPU1 EEPROM. VC8; Per SSR read Variable depending on amount of file data dumped.
EPU2 file dump to SSR 978 (0x3D2) This telemetry contains contents of selected files stored in EPU2 EEPROM. VC8; Per SSR read Variable depending on amount of file data dumped.
SIU MSG system traffic to SSR 960 (0x3C0) This telemetry contains the low-level message traffic issued by FSW tasks at a configurable level of verbosity. VC8; Per SSR read. Variable depending on per-CPU, per-task MSG severity settings.
EPU0 MSG system traffic to SSR 961 (0x3C1) See 960 above. VC8; Per SSR read. Variable depending on per-CPU, per-task MSG severity settings.
EPU1 MSG system traffic to SSR 962 (0x3C2) See 960 above. VC8; Per SSR read. Variable depending on per-CPU, per-task MSG severity settings.
EPU2 MSG system traffic to SSR 963 (0x3C3) See 960 above. VC8; Per SSR read. Variable depending on per-CPU, per-task MSG severity settings.
Register dump data 928 (0x3A0) Contents of user-selected electronics registers. This data is accessed using telecommands from the LAT Register Access system. If less than 4K of this data are requested, the data can also be sent over the 1553 interface. VC8; Per SSR read. Variable, depending on the number of registers selected.
Current detector configuration (LATC defined) 1021 (0x3FD) This telemetry contains the contents of the in-memory LAT register configuration model. VC8; Per SSR read TBD.
Current power system configuration (PIG defined) 1022 (0x3FE) This telemetry reports the PDU register configuration. VC8; Per SSR read TBD.