Comtech EF Data HPCST-5000 - Manual (Page 80)

Single Thread System Installation High-Power TWTA Satellite Terminals
2–34 Rev.1
1. High Voltage ON Indicator (Pin 8). (Active = low.) When active, indicates that
the amplifier is ON, i.e., the transistor is turned ON and the collector Pin 8 (+) is
pulled to the emitter (Pin 7). Maximum open voltage is 20V and maximum
switched current is 3 mA. The switch is an isolated photo-coupler.
Return = Pin 7.
2. Summary Fault Indicator (Pin 10). (Active = low.) When active, indicates there
is fault within the amplifier, i.e., the transistor is turned ON and the collector
Pin 10 (+) is pulled to the emitter (Pin 22). Maximum open voltage is 20V and
maximum switched current is 3 mA. The switch is an isolated photo-coupler.
Return = Pin 22.
3. The faults included are:
a. Helix Over-Current
b. High Voltage
c. Over-Voltage/Under-Voltage
d. Over-Current (Triggering HV Fault)
e. Power Supply Over-Temperature
4. High Voltage Select ON Indicator (Pin 12). (Active = low.) When active,
indicates the High Voltage ON command has been selected, i.e., the transistor is
turned ON and the collector Pin 12 (+) is pulled to the emitter (Pin 24).
Maximum open voltage is 20V and maximum switched current is 3 mA. The
switch is an isolated photo-coupler. Return = Pin 24.
5. Standby Indicator (Pin 21). (Active = low.) When active, indicates the unit is
ready for on-line service, i.e., the transistor is turned ON and the collector Pin 21
(+) is pulled to the emitter (Pin 9). Maximum open voltage is 20V and maximum
switched current is 3 mA. The switch is an isolated photo-coupler.
Return = Pin 9.
6. FTD (Filament Time Delay) Indicator (Pin 23). (Active = low.) When active,
indicates the Filament Time Delay cycle is in progress, i.e., the transistor is
turned ON and the collector Pin 23 (+) is pulled to the emitter (Pin 11).
Maximum open voltage is 20V and maximum switched current is 3 mA. The
switch is an isolated photo-coupler. Return = Pin 11.
7. Local/Remote Indicator (Pin 25). (Active = low.) When active, indicates the
front panel Local/Remote switch has been set to Remote, i.e., the transistor is
turned ON and the collector Pin 25 (+) is pulled to the emitter (Pin 13).
Maximum open voltage is 20V and maximum switched current is 3 mA. The
switch is an isolated photo-coupler. Return = Pin 13.