Mark IID/IIDG Interface & Umbilical Connectors

The various ST5000 electronics modules are wired through the harness to 3 top-level connectors and one umbilical connector, which provide the interface to the outside world. This photo shows the 3 top-level connectors along the top.

A note on the items CMD0-CMD7: these are the "hardware" digital inputs, bits you can assert to control the ST5000 directly from the electrical connections. They are active low, and you connect them to SIG-GND to assert them. Each has a parallel "software" input bit, commandable via ascii commands sent in on either COM2 or COM3.

J651: DC-37S, TM Interface, Mating Connector: DC-37P

Pin Signal Comment Pin Signal Comment
1 N/A
20 N/A
2 N/A
21 N/A
3 CMD2 LIS Test (pretend to succeed in Lost-in-Space) 22 N/A
4 CMD3 Blobmode Enable (accept badly formed star image) 23 SIG-GND3 Ground reference for commands and monitors
5 CMD4 Acquire (acquire and start tracking) 24 CMD0-MON No Connect
6 CMD5 LIS Enable (do Lost-in-Space on next acquire) 25 CMD1-MON No Connect
7 CMD6 PIT Enable (do Progressive Image Transmission on next acquire) 26 CMD2-MON No Connect
8 DOB4-MON TTL High/Low = Heartbeat Good 27 CMD3-MON No Connect
9 DOB5-MON TTL High = Tracker Locked 28 CMD4-MON No Connect
10 DOB6-MON TTL HIGH = LIS Active 29 CMD5-MON No Connect
11 DOB7-MON TTL High = PIT Active 30 CMD6-MON No Connect
12 PITCH-ERR-MON Pitch Error = -2.4*(VMON-2.5) 31 CMD7-MON No Connect
13 YAW-ERR-MON Yaw Error = -2.4*(VMON-2.5) 32 BUS-V-MON V Bus = 20.0 * VMON
14 ROLL-ERR-MON Roll Error = -2.4*(VMON-2.5) 33 BUS-I-MON I Bus = 1.0 (A/V) * VMON
15 STAR-MAG-MON Star Mag = 8*(1 - 0.2*VMON) 34 SIG-GND4 Ground reference for commands and monitors
16 COM1-TM-TXD+ RS422 Downlink of long telemetry packets 35 COM1-TM-TXD- RS422 Downlink of long telemetry packets
17 COM1-TM-GND RS422 Downlink of long telemetry packets 36 COM4-ACS-ECHO-GND RS422 Downlink of short ACS packets
18 COM4-ACS-ECHO-TXD+ RS422 Downlink of short ACS packets 37 COM4-ACS-ECHO-TXD- RS422 Downlink of short ACS packets
19 CABLE SHIELD No connect


J652:DA-15P, ACS Interface, Mating Connector: DA15S

Pin Signal Comment Pin Signal Comment
1 +28V(A) +28V +/- 8V @ 0.6A power in 9 28V-RET(A) +28V power ground return
2 +28V(B) +28V +/- 8V @ 0.6A power in (redundant) 10 28V-RET(B) +28V power ground return (redundant)
3 COM2-ACS-TXD+ Bi-Directional RS422 comms, sends short ACS packet 11 COM2-ACS-TXD- Bi-Directional RS422 comms, sends short ACS packets
4 COM2-ACS-RXD+ Bi-Directional RS422 comms, receives commands 12 COM2-ACS-RXD- Bi-Directional RS422 comms, receives commands
5 N/A
13 COM2-ACS-GND Bi-Directional RS422 comms from ACS
6 CMD0 HRTB (High Rate Track Boxes, not used) 14 SIG-GND-1 Ground reference for commands and monitors
7 CMD1 ACS-Enable (start sending short ACS packets on COM2) 15 SIG-GND-2 Ground reference for commands and monitors
8 CABLE SHIELD No Connect


J653: DB-25S, Diagnostic Interface, Mating Connector: DB-25P

Pin Signal Comment Pin Signal Comment
1 NET-TX+ Network (TCP/IP) 14 NET-TX- Network (TCP/IP)
2 NET-RX+ Network (TCP/IP) 15 NET-RX- Network (TCP/IP)
3 COM3-RXD Bi-Directional RS232 comms on UMBI, receives commands 16 MS-DATA Mouse Data
4 COM3-TXD Bi-Directional RS232 comms on UMBI, sends long telemetry packets 17 COM3-GND Bi-Directional RS232 comms on UMBI
5 KB-DATA Keyboard Data 18 KB+5 Keyboard +5 Volts
6 KB-CLK Keyboard Clock 19 KB-GND Keyboard Ground
7 SPKR-A Speaker 20 SPKR-B Speaker
8 TP-BAT Test Point - real-time clock battery 21 CPU-GND Real-time clock battery ground reference
9 +12V Internal Power Out 22 DGND Internal Power Ground;
Ground reference for CPU reset and CMD7
10 -12V Internal Power Out 23 CPU-RST-2N CPU Reset: active low, connect to DGND to assert
11 +5V Internal Power Out 24 CMD7 Flight/Test mode: active low, low = test mode, connect to DGND to assert
12 MS-CLK Mouse Clock 25 CHASS-GND Chassis Ground
13 CABLE SHIELD No Connect


J655: DA-15P, Umbilical Interface Connector for 486 Controllers

Pin Signal Comment Pin Signal Comment
1 ISO +12V Umbi Remote Power In 9 ISO GND Umbi Remote Power Return
2 RD (A) RS-422 to Tracker 10 RD (B) RS-422 to Tracker
3 TD (A) RS-422 from Tracker 11 TD (B) RS-422 From Tracker
4 TSTN (H) Test Bit 20 mA In 12 TSTN (L) Test Bit 20 mA Return
5 N/A No Connect 13 N/A No Connect
6 N/A No Connect 14 N/A No Connect
7 N/A No Connect 15 N/A No Connect
8 N/A No Connect


J673: DA-15P, Umbilical Interface Connector for Geode Controller
with ST5267 Module, Rev D and Earlier

Pin Signal Comment Pin Signal Comment
1 ISO +12V Umbi Remote Power In 9 ISO GND Umbi Remote Power Return
2 RD (A) RS-422 to Tracker 10 RD (B) RS-422 to Tracker
3 TD (A) RS-422 from Tracker 11 TD (B) RS-422 From Tracker
4 TSTN (H) Test Bit 20 mA In 12 TSTN (L) Test Bit 20 mA Return
5 N/A No Connect 13 N/A No Connect
6 N/A No Connect 14 N/A No Connect
7 N/A No Connect 15 N/A No Connect
8 N/A No Connect


J673: DE-9P, Umbilical Interface Connector for Geode Controller
with ST5267 Module, Rev E and Later

Pin Signal Comment Pin Signal Comment
1 ISO +12V Umbi Remote Power In 6 ISO GND Umbi Remote Power Return
2 RD (A) RS-422 to Tracker 7 RD (B) RS-422 to Tracker
3 TD (A) RS-422 from Tracker 8 TD (B) RS-422 From Tracker
4 TSTN (H) Test Bit 20 mA In 9 TSTN (L) Test Bit 20 mA Return
5 N/A No Connect