Comtech EF Data CST-5005 - Manual (Page 78)

Theory of Operation CST-5005 C-Band Satellite Terminal
5–8 Rev. 1
5.1.5.4 U/C and HPA, J3 DB25-Female
Pin # Name Description
1 UC 12V Output power to UC
14 HPA 12V Output power to high-power amplifier
2 HPA 12V Output power to high-power amplifier
15 N/C
3 HPA GAIN CNTL Output, 0 to 4V for gain control of high-power
amplifier
16 RF OFF Output, open collector, 0 = OFF
4 N/C
17 N/C
5 N/C
18 HPA FLT NO Input, Open = Fault
6 HPA FLT COM Output, ground connection to relay common
19 HPA FLT NC Input, Open = Normal
7 N/C
20 HPA THERM Input, 10K thermistor to ground located in high-
power amplifier
8 UC THERM Input, 10K thermistor to ground located in UC
21 UC GAIN CNTL1 Output, 0 to 4 VDC for gain control of UC
9 UC GAIN CNTL2 Output, 0 to 4 VDC for gain control of UC
22 SDA Bidirectional, CMOS serial data
10 SCL Output, CMOS serial clock
23 SPARE
11 SPARE
24 SPARE
12 HPA GND Ground
25 HPA GND Ground
13 UC GND Ground