GALILEO
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Galileo Table of Contents Page.
The Galileo Energetic Particles Detector
Galileo EPD Handbook
Chapter 1. Instrument Summary
Galileo EPD Housekeeping Functions (continued)
Source: R. C. Moore, August 26, 1979
Table 2. Galileo EPD Subcommutated Housekeeping
Documents marked with * are not available on this website; reference APL S3 Division archives.
| Cursor Value | Function | Conversion Rule | Comments |
| 1 | Motor housing temperature (originally analog) | (See Engineering Unit Conversion Function for Temperatures in *S3D-70-000.) | High and low alarm thresholds are in functions with cursor values 55 and 56. |
| 2 | Motor telemetry byte #1 | Bit 1 - Scan error 0 ® no error 1 ® error |
(A detailed description of the
motor telemetry is found in *EPD-085-79.) Scan error indicates that more pulses were delivered to the motor to make a sector change than should have been necessary. |
| Bit 2 - Fast scan
abort flag 0 ® normal 1 ® abort |
Fast scan abort indicates that the fast scan mode was automatically aborted due to excessive depth of discharge of motor capacitor bank. Returns to normal scan. | ||
| Bit 3 - Emergency
count flag 0 ® normal 1 ® emergency count number, modulo 32, occupies bits 4-8 instead of motor position data |
In the emergency mode, whenever the motor is between sectors, this bit goes to logic 1. Emergency count number is the number of 1.8° steps attempted since the motor was last on sector centerline. | ||
| Bit 4 - Direction
indicator 0 ® counterclockwise 1 ® clockwise |
Clockwise means sector numbers are increasing. | ||
| Bit 5 - Centerline
indicator 0 ® off center 1 ® on center |
Marks center (±1.3°) of sector. | ||
| Bits 6-8 - Motor
position code P = 4B6 + 2B7 + B8 |
P is the sector number. | ||
| 3 | Motor telemetry byte #2 | Bit 1 - Emergency
mode indicator 0 ® normal 1 ® emergency |
In emergency mode, motor moves one step per trigger instead of one sector per trigger. |
| Bit 2 - Open loop
mode indicator 0 ® closed loop 1 ® open loop |
In closed loop mode, the motor moves until the next centerline is found or an automatic cease scan occurs. In open loop mode, a fixed number of steps is applied to the motor, to change sectors. | ||
| Bit 3 Modified scan (closed loop mode) 0 ® normal scan using end sectors 0 and 7 1 ® Modified scan using end sectors programmed by ground command Limited scan (open loop mode) 0 ® normal scan 1 ® limited scan |
For detailed descriptions of normal scan and limited scan, see *EPD-085-79. | ||
| Bit 4 - Fast scan 0 ® normal scan 1 ® fast scan |
Fast scan: motor receives triggers every two logical records (every 2-2/3 seconds). | ||
| Bit 5 Go to sector N (closed loop mode) 0 ® normal 1 ® go to sector N and stay there Respond to N triggers (open loop mode) 0 ® normal 1 ® stop scanning after N triggers |
Value of N is found in bits 6, 7, and 8. | ||
| Bits 6-8 - "N" N = 4B6 + 2B7 + B8 |
|||
| 4 | Motor telemetry byte #3 | Bit 1 - Alternate
step rate mode 0 ® normal 1 ® alternate step rate |
Normal: ~50 steps/sec (~90°/sec) Alternate: ~60 steps/sec (108°/sec) |
| Bits 2-4 - CCW
end-sector Sccw = 4B2 + 2B3 + B4 |
Bits 2-4 are not used in open loop mode. | ||
| Bit 5 - Chicken Mode
(closed loop mode) 0 ® normal 1 ® chicken mode |
"Chicken Mode" is a mode in which most of the time is spent behind the shield (sector 0). (Not used in open loop mode.) | ||
| Bits 6-8 - CW
end-sector Scw = 4B6 + 2B7 + B8 |
Bits 6-8 are not used in open loop mode. | ||
| 5 | Autocalibrator index #1 | I1 =
64B2 + 32B3 + 16B4 +
8B5 + 4B6 + 2B7 +
B8 B1 is ignored. |
This index identifies contents of next subcommutated function, according toTable 1 and *EPD-050-79. |
| 6 | Autocalibrator AGC voltage #1 (originally analog) | AGC1 = 2.56B1 + 1.28B2 + .64B3 + .32B4 + .16B5 + .08B6 + .04B7 + .02B8 | 0 volts £ AGC £ 5.1 volts |
| 7 | Motor telemetry byte #4 | N = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | N = number of invalid motor commands, modulo 256. |
| 8 | Motor telemetry byte #5 | Bits 1 & 2 not used. Bits 3-7 - step count (closed loop mode) SC = 16B3 + 8B4 + 4B5 + 2B6 + B7 Bits 3-7 not used in open loop mode. |
Step count is the number of steps required to make the most recent sector change. |
| Bit 8 - cease scan
flag (closed loop mode) 0 ® normal 1 ® cease scan Bit 8 not used in open loop mode. |
"Cease scan" indicates that the motor was unable to find a centerline during a closed loop sector change attempt. Motor automatically tries to return to centerline of previous sector. | ||
| 9 | LEMMS telescope temperature (originally analog) | (See Engineering Unit Conversion Function for Temperatures in *S3D-79-000.) | High and low alarm thresholds are in functions with cursor values 61 and 62. |
| 10 | Number of invalid bus commands, modulo 256 | NIC = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | NIC is the sum of invalid data system commands and invalid scanning system commands. Function at cursor 7 is scanning system invalid command count. |
| 11 | Autocalibrator index #2 | (Same as for cursor #5) | See *EPD-050-79. |
| 12 | Autocalibrator AGC voltage #2 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 13 | Memory dump cursor (8 MSBs) | MDC = 32768B1 + 16384B2 + 8192B3 + 4096B4 + 2048B5 + 1024B6 + 512B7 + 256B8 + (least significant half) | Least significant half of MDC is in channels 9 and 95 of the EPD logical record (see *S3D-79-093). |
| 14 | Motor dwell period | MDP = 170.67B1 + 85.33B2 + 42.67B3 + 21.33B4 + 10.67B5 + 5.33B6 + 2.67B7 + 1.33B8 | MDP is programmable by ground command in integer multiples of 1.333 seconds. During accelerated scan, MDP = 2.667. Default (initial) value for MDP is 20 seconds. |
| 15 | CMS telescope temperature (originally analog) | (See Engineering Unit Conversion Function for Temperatures in *S3D-79-000.) | High and low alarm thresholds are in functions with cursor values 67 and 68. |
| 16 | Supervisory data parity error count | SDP = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | SDP is the number of parity errors detected by EPD bus adapter since last power-on, modulo 256. |
| 17 | Autocalibrator index #3 | (Same as for cursor #5) | See *EPD-050-79. |
| 18 | Autocalibrator AGC voltage #3 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 19 | Upper memory checksum limit (8 MSBs) | UMCL = 32768B1 + 16384B2 + 8192B3+ 4096B4 + 2048B5 + 1024B6 + 512B7 + 256B8 + (least significant half) | Least significant half of UMCL is in function with cursor value = 20. |
| 20 | Upper memory checksum limit (8 LSBs) | UMCL = 128B1 + 64B2 + 32B3 + 16B4+ 8B5 + 4B6 + 2B7 + B8 + (most significant half) | Most significant half of UMCL is in function with cursor value = 20. |
| 21 | Main electronics temperature (originally analog) | (See Engineering Unit Conversion Function for Temperatures in *S3D-79-000.) | High and low alarm thresholds are in functions with cursor values 73 and 74. |
| 22 | Memory checksum | MCM = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | |
| 23 | Autocalibrator index #4 | (Same as for cursor #5) | See *EPD - 050-79. |
| 24 | Autocalibrator AGC voltage #4 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 25 | Lower memory checksum limit (8 MSBs) | LMCL = 32768B1 + 16384B2 + 8192B3+ 4096B4 + 2048B5 + 1024B6 + 512B7 + 256B8 + (least significant half) | Least significant half of LMCL is in function with cursor value = 26. |
| 26 | Lower memory checksum limit (8 LSBs) | LMCL = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 + (most significant half) | Most significant half of LMCL is in function with cursor value = 25. |
| 27 | EPD input current (originally analog) | (See Engineering Unit Conversion Function for Current in *S3D-79-000.) | High and low alarm thresholds are in functions with cursor values 49 and 50. |
| 28 | EPD data parity error count | EDP = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | EDP is the number of parity errors detected by EPD bus adapter during EPD bus transactions since last power-on, modulo 256. |
| 29 | Autocalibrator index #5 | (Same as for cursor #5) | See *EPD-050-79. |
| 30 | Autocalibrator AGC voltage #5 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 31 | LEMMS PHA A K1 | AK1 = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | 0 £ A K1 £ 192 |
| 32 | LEMMS PHA A K2 | AK2 = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | 0 £ A K2 £ 2 |
| 33 | +60 volts bias (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 34 | Power switch status byte #1 | Bit n = 0 ® LEMMS
AMP (9-n) off Bit n = 1 ® LEMMS AMP (9-n) on |
1 £ n £ 8 (See *S3D-79-104.) |
| 35 | Autocalibrator index #6 | (Same as for cursor #5) | See *EPD-050-79. |
| 36 | Autocalibrator AGC voltage #6 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 37 | LEMMS PHA E K1 | EK1 = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | 0 £ E K1 £ 192 |
| 38 | LEMMS PHA E K2 | EK2 = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | 0 £ E K2 £ 2 |
| 39 | +20 volts bias (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 40 | Power switch status byte #2 | B1 -
spare B2 = 1 ® calibrator on B2 = 0 ® calibrator off B3 = 1 ® PHA on B3 = 0 ® PHA off B4 = 0 ® TOF on B4 = 0 ® TOF off B5 = 1 ® CMS electronics on B5 = 0 ® CMS electronics offCMS electronics off B6 = 1 ® Detector bias high B6 = 0 ® Detector bias normalDetector bias normal B7 = 1 ® CMS J' bias on (+20V) B7 = 0 ® CMS J' bias offCMS J' bias off B8 = 1 ® LEMMS A detector bias on (+60V) B8 = 0 ® LEMMS A detector bias off |
(See *S3D-79-104.) |
| 41 | Autocalibrator index #7 | (Same as for cursor #5) | See *EPD-050-79. |
| 42 | Autocalibrator AGC voltage #7 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 43 | LEMMS PHA F K1 | FK1 = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | 0 £ F K1 £ 192 |
| 44 | LEMMS PHA F K2 | FK2 = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | 0 £ F K2 £ 2 |
| 45 | -15 Volts power (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 46 | Power switch status byte #3 | B1 =
1 ® LEMMS
-10V power on B1 = 0 ® LEMMS -10V power off B2 = 1 ® motor on B2 = 0 ® motor off B3 = 1 ® motor RAM exchanged B3 = 0 ® motor RAM normal B4 B5 B6 - spares B7 = 1 ® LEMMS E11LEMMS E11 thresh. high B7 = 0 ® LEMMS E11 thresh. normal B8 = 1 ® LEMMS A1 thresh. high B8 = 0 ® LEMMS A1 thresh. normal |
|
| 47 | Autocalibrator index #8 | (Same as for cursor #5) | See *EPD-050-79. |
| 48 | Autocalibrator AGC voltage #8 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 49 | Upper alarm threshold for EPD input current | UTIC = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | Engineering unit conversion is in *S3D-79-000. |
| 50 | Lower alarm threshold for EPD input current | LTIC = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor 49. |
| 51 | +10 Volts power (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 52 | Power switch status byte #4 | B1 =
1 ® TOF
logical condition off B1 = 0 ® TOF logical condition on B2 - spare B3 = 1 ® CMS analog J'K' on B3 = 0 ® CMS analog J'K' off B4 = 1 ® CMS analog L on B4 = 0 ® CMS analog L off B5 = 1 ® CMS analog Jc on B5 = 0 ® CMS analog Jc off B6 = 1 ® CMS analog Jb on B6 = 0 ® CMS analog Jb off B7 = 1 ® CMS analog Ja on B7 = 0 ® CMS analog Ja off B8 = 1 ® CMS prime select on B8 = 0 ® CMS prime select off |
|
| 53 | Autocalibrator index #9 | (Same as for cursor #5) | See *EPD-050-79. |
| 54 | Autocalibrator AGC voltage #9 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 55 | Upper alarm threshold for motor temperature | UTMT = 128B1 + 64B2 + 32B3 + 16B4+ 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 56 | Lower alarm threshold for motor temperature | LTMT = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 57 | +6 Volts power (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 58 | PHA control byte | B1 =
EP1 priority = 2 EP1 +
EP0 B2 = EP0 " " " B3 = 0 ® priority override B3 = 1 ® priority normal B4 = 1 ® PHA reset B4 = 0 ® PHA normal B5 = LS1 LEMMS select = 2 LS1 + LS0 B6 = LS0 " " " B7 = 0 ® P read active B7 = 1 ® P read inactive B8 = 0 ® LEMMS mode B8 = 1 ® CMS mode |
|
| 59 | Autocalibrator index #10 | (Same as for cursor #5) | See *EPD-050-79. |
| 60 | Autocalibrator AGC voltage #10 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 61 | Upper alarm threshold for LEMMS telescope temperature | UTLT = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 62 | Lower alarm threshold for LEMMS telescope temperature | LTLT = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 63 | +3 Volts power (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 64 | (spare) | ||
| 65 | Autocalibrator index #11 | (Same as for cursor #5) | See *EPD-050-79. |
| 66 | Autocalibrator AGC voltage #11 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 67 | Upper alarm threshold for CMS telescope temperature | UTCT = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 68 | Lower alarm threshold for CMS telescope temperature | LTCT = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 69 | -3 Volts power (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 70 | (spare) | ||
| 71 | Autocalibrator index #12 | (Same as for cursor #5) | See *EPD-050-79. |
| 72 | Autocalibrator AGC voltage #12 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 73 | Upper alarm threshold for main electronics temperature | UTET = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 74 | Lower alarm threshold for main electronics temperature | LTET = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | See comment at cursor #49. |
| 75 | -6 Volts power (originally analog) | (See Engineering Unit Conversion Function in S*3D-79-000.) | |
| 76 | (spare) | ||
| 77 | Autocalibrator index #13 | (Same as for cursor #5) | See *EPD-050-79. |
| 78 | Autocalibrator AGC voltage #13 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 79 | Upper alarm threshold #6 |
 |
|
| 80 | Lower alarm threshold #6 |
 |
|
| 81 | -10 Volts power (originally analog) | (See Engineering Unit Conversion Function in *S3D-79-000.) | |
| 82 | (spare) | ||
| 83 | Autocalibrator index #14 | (Same as for cursor #5) | See *EPD-050-79. |
| 84 | Autocalibrator AGC voltage #13 (originally analog) | (Same as for AGC1 - see cursor #6.) | |
| 85 | (spare) | ||
| 86 | (spare) | ||
| 87 | Dust cover deployment (originally analog) | DC = 128B1 + 64B2 + 32B3 + 16B4 + 8B5 + 4B6 + 2B7 + B8 | 0 £ DC £ 32 ® covers
closed. 33 £ DC £ 96 ® sector 1 cover open, sector 7 cover closed. 97 £ DC £ 137 ® sector 1 cover closed, sector 7 cover open. 138 £ DC £ 255 ® both covers open. |
| 88 | (spare) | ||
| 89 | (spare) | ||
| 90 | (spare) | ||
| 91 | (spare) |
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Updated 8/23/19, Cameron Crane
QUICK FACTS
Manufacturer: The Galileo Spacecraft
was manufactured by the Jet Propulsion Laboratory,
Messerschmitt-Bölkow-Blohm, General Electric, and the
Hughes Aircraft Company.
Mission Duration: Galileo was planned to have a mission duration of around 8 years, but was kept in operation for 13 years, 11 months, and 3 days, until it was destroyed in a controlled impact with Jupiter on September 21, 2003.
Destination: Galileo's destination was Jupiter and its moons, which it orbitted for 7 years, 9 months, and 13 days.
Mission Duration: Galileo was planned to have a mission duration of around 8 years, but was kept in operation for 13 years, 11 months, and 3 days, until it was destroyed in a controlled impact with Jupiter on September 21, 2003.
Destination: Galileo's destination was Jupiter and its moons, which it orbitted for 7 years, 9 months, and 13 days.