karn@mouton.UUCP (06/22/84)
From the University of Surrey. The following text is reproduced from one of our datasheet handouts, in response to a couple of requests for the latest revision of Oscar-11 telemetry equations. UoSAT-2 Telemetry Data Format The telemetry system collects 60 analogue values from around the spacecraft, digitises them and sends the results, together with 96 status points, a 'UOSAT-2' identifier and the time, to the beacon multiplexers as a serial ASCII stream. The data is transmitted at 300, 600, 1200 or 2400 baud, using a standard character format of 1 start bit, 7 data bits, 1 even parity bit and 2 stop bits. There is no Morse code or RTTY available from the telemetry system directly, but these formats could be generated by the 1802 computer. The 2400 baud rate is experimental and can only be modulated using a different format - a separate datasheet will explain this. A typical 'frame' of data contains 7 rows of 10 'channels' of information. This is illustrated below: UOSAT-2 8405174112923 00380 01370 02661 03481 04059 05046 06027 07056 08040 09033 10512 11357 12000 13089 14000 15000 16000 17487 18467 19572 20523 21061 22659 23000 24000 25000 26104 27483 28600 29544 30435 31040 32283 33000 34000 35378 36434 37460 38529 39539 40855 41000 42674 43000 44171 45001 46000 47528 48541 49509 50569 51073 52702 53295 54990 55000 56000 57535 58532 59535 60800 615BC 62800 63024 64000 65000 66C00 67000 68000 69000 The first two digits in each channel are the channel identifier, a decimal number between 0 and 69. Channels 0 to 59 are the 60 analogue values, and the 3-digit decimal number following the identifier is the value 'N' which may be substituted into the calibration equations below. Channels 60 to 67 contain the 96 status points, held as 3 hexadecimal digits, e.g. channel 61 contains bits 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24, with 13 as the MSB and 24 as the LSB. (i.e. 61400 means that bit 14 is set and bits 13 and 15-24 are zero). Channels 68 and 69 are always zero. A 1Eh cursor home character preceeds 'UOSAT-2' in each frame, and the identifier is followed by the date/time in the format YYMMDDWHHMMSS, where W is the day of the week, 0 to 6. Following experience on UoSAT-1, a checksum character has been included in the telemetry system hardware (rather than using the computer as before). The above frame, with checksums, is as follows: UOSAT-2 8405174112923 00380B01370502661303481E04059805046706027307056408040C090339 10512711357112000313089314000515000416000717487D18467C195728 20523621061422659A23000124000625000726104127483A28600C29544E 30435131040632283833000034000735378A364346374606385295395395 40855C41000542674343000744171745001046000247528C48541C495091 50569F51073052702253295854990155000056000357535158532959535F 60800E615BC562800C63024364000265000366C00C67000168000E69000F The checksum characters have been substituted in the place of the spaces following each channel. By exclusive-or'ing the binary (0-15) values of all 6 characters in each channel, (2 identifiers, 3 data & 1 checksum), a non-zero result indicates that the channel has been corrupted in transmission. A zero result, of course, does not guarantee a correct channel! A dwell format is also available, in which an unlimited number of channels may be selected and displayed in virtually any format, checksummed or non-checksummed. The identifier and time-stamp are optional in this mode. UoSAT-2 Telemetry Calibration Equations Chan no. Name Equation 00 Solar array current -Y I=1.9(516-N) ma 01 Nav mag X axis H=(0.1485N-68) uT 02 Nav Mag Z axis H=(0.1523N-69.3) uT 03 Nav mag Y axis H=(0.1507N-69) uT 04 Sun sensor no. 1 05 Sun sensor no. 2 06 Sun sensor no. 3 07 Sun sensor no. 4 08 Sun sensor no. 5 09 Sun sensor no. 6 10 Solar array current +Y I=1.9(516-N) mA 11 Nav mag (Wing) temp T=(330-N)/3.45 C 12 Horizon sensor 13 Spare (tbd) 14 DCE RAMUNIT current I=(N-70.4)/6.7 mA 15 DCE CPU current I=(N-187.1)/2.0 mA 16 DCE GMEM current I=(N-121.3)/2.1 mA 17 Facet temp +X T=(480-N)/5 C 18 Facet temp +Y T=(480-N)/5 C 19 Facet temp +Z T=(480-N)/5 C 20 Solar array current -X I=1.9(516-N) mA 21 +10V line current I=0.97N mA 22 PCM voltage +10V V=0.015N V 23 P/W logic current (+5V) I=0.14 (N<=500) 24 P/W Geiger current (+14V) I=0.21N mA 25 P/W Elec sp.curr (+10V) I=0.096N mA 26 P/W Elec sp.curr (-10V) I=0.093 mA 27 Facet temp -X T=(480-N)/5 C 28 Facet temp -Y T=(480-N)/5 C 29 Facet temp -Z T=(480-N)/5 C 30 Solar array current +X I=1.9(516-N) mA 31 -10V line current I=0.48N mA 32 PCM voltage -10V V=0.036N V 33 1802 comp curr (+10V) I=0.21N mA 34 Digitalker current (+5V) I=0.13N mA (N<=500) 35 145MHz beacon power O/P P=(2.5N - 275) mW (N>200) 36 145MHz beacon current I=0.22N mA 37 145MHz beacon temp T=(480-N)/5 C 38 Command decoder temp (+Y) T=(480-N)/5 C 39 Telemetry temp (+X) T=(480-N)/5 C 40 Solar array voltage (+30V) V=(0.1N-51.6) V 41 +5V line current I=0.97N mA 42 PCM voltage +5V V=0.0084N V 43 DSR current (+5V) I=0.21N mA (n<=500) 44 Command RX current I=0.92N mA 45 435MHz beacon power O/P P=(2.5N-200) mW N>175 46 435MHz beacon current I=0.44N mA 47 435MHz beacon temp T=(480-N)/5 C 48 P/W temp (-X) T=(480-N)/5 C 49 BCR temp (-Y) T=(480-N)/5 C 50 Battery charge/dischg curr I=8.8(N-513) mA 51 +14V line current I-5N mA 52 Battery voltage (+14V) V=0.021N V 53 Battery cell volts (MUX) See below 54 Telemetry current (+10V) I=0.02N mA 55 2.4GHz beacon power O/P P=((N+50)**2)/480 mW 56 2.4GHz beacon current I=0.45N mA 57 Battery temp T=(480-N)/5 C 58 2.4GHz beacon temp T=(480-N)/5 C 59 CCD imager temp T=(480-N)/5 C 60-67 Status points 1-96 Multiplexed Battery Scheme (channel 53) Six consecutive TLM frames will carry the total volts, the following ten frames will be individual cells, starting with cell no. 10. Each cell has its own equation. The calibrations will be supplied later. UOSAT-2 Status Points Telemetry No. Item State Frame No. 60 (MSB) 1 145 MHz General Beacon power Off/On 60 2 435 MHz Engineering Beacon power Off/On 60 3 2401 MHz Engineering Beacon power Off/On 60 4 Telemetry channel mode select Run/Dwell 60 5 Telemetry channel dwell address load Off/On 60 6 Telemetry channel dwell address source Gnd/Computer 60 7 Primary Spacecraft Computer power Off/On 60 8 Primary Spacecraft Computer error count Bit 1 60 9 Primary Spacecraft Computer error count Bit 2 60 10 Primary Spacecraft Computer bootstrap PROM/UART 60 11 Primary Spacecraft Computer error count Bit 3 60 (LSB) 12 Primary Spacecraft Computer bootstrap A/B 61 (MSB) 13 Gravity gradient boom deployment pyros Safe/Arm 61 14 Gravity gradient boom deployment pyros Hold/Fire 61 15 Gravity gradient boom deployment Safe/Arm 61 16 Gravity gradient boom deployment Hold/Deploy 61 17 Gravity gradient boom deployment Extend/Retract 61 18 Attitude Control Magnetorquers Safe/Arm 61 19 Attitude Control Magnetorquer -X On/Off 61 20 Attitude Control Magnetorquer -Y On/Off 61 21 Attitude Control Magnetorquer -Z On/Off 61 22 Attitude Control Magnetorquer Reverse/Forward 61 23 435 MHz PSK mode NRZI/NRZIC 61 (LSB) 24 2401 MHz PSK mode NRZI/NRZIC 62 (MSB) 25 Attitude Control Magnetorquers High/Low power 62 26 Digitalker expt. power Off/On 62 27 CCD Camera expt. power Off/On 62 28 CCD Camera expt. integration period Bit 0 62 29 CCD Camera expt. integration period Bit 1 62 30 CCD Camera expt. video amp gain Bit 0 62 31 CCD Camera expt. video amp gain Bit 1 62 32 DSR power Off/On 62 33 DSR mode Read/Write 62 34 DSR mode Run/Reset 62 35 Radiation Detectors Geiger-A EHT power Off/On 62 (LSB) 36 Radiation Detectors Geiger-B EHT power Off/On 63 (MSB) 37 Radiation Detectors Geiger-C EHT power Off/On 63 38 Electron Spectrometer sensor EHT power Off/On 63 39 DCE expt. power Off/On 63 40 DCE expt. Reset/Run 63 41 DCE expt. PROM select A/B 63 42 DCE expt. CPU clock rate select 0.9/1.8 MHz 63 43 Navigation Magnetometer power Off/On 63 44 Space Dust experiment power Off/On 63 45 Status calibrate 63 46 BCR status 0/1 63 47 435 MHz beacon modulation select AFSK/PSK 63 (LSB) 48 2401 MHz beacon modulation select AFSK/PSK 64 (MSB) 49 Engineering data Bit 1 64 50 Engineering data Bit 2 64 51 Engineering data Bit 3 64 52 Engineering data Bit 4 64 53 Engineering data Bit 5 64 54 Command Watchdog Disable/Enable 64 55 Command Watchdog reset 0/1 64 56 145 MHz beacon data select A 64 57 145 MHz beacon data select B 64 58 145 MHz beacon data select C 64 59 145 MHz beacon data select D 64 (LSB) 60 145 MHz beacon data select E 65 (MSB) 61 145 MHz beacon data select F 65 62 145 MHz beacon data rate A 65 63 145 MHz beacon data rate B 65 64 435 MHz beacon data rate A 65 65 435 MHz beacon data rate B 65 66 435 MHz beacon data rate C 65 67 Particle / Wavecounter control Count/Reset 65 68 Beacon lockout latch Enable/Disable 65 69 Engineering data Bit 6 65 70 Engineering data Bit 7 65 71 Engineering data Bit 8 65 (LSB) 72 Engineering data Bit 9 66 (MSB) 73 P/W channel plate control Bit 0 66 74 P/W channel plate control Bit 1 66 75 P/W channel plate control Bit 2 66 76 Space Dust (MSB) 66 77 Space Dust 66 78 Space Dust 66 79 Space Dust 66 80 Space Dust 66 81 Space Dust 66 82 Space Dust 66 83 Space Dust (LSB) 66 (LSB) 84 DSR write cycle complete 67 (MSB) 85 1802 CWO output 67 86 1802 Telemetry port (MSB) 67 87 1802 Telemetry port 67 88 1802 Telemetry port 67 89 1802 Telemetry port 67 90 1802 Telemetry port 67 91 1802 Telemetry port 67 92 1802 Telemetry port 67 93 1802 Telemetry port 67 94 1802 Telemetry port 67 95 1802 Telemetry port 67 (LSB) 96 1802 Telemetry port (LSB) The 'engineering data' bits contain the internal status of certain modules and are unlikely to be of general interest.