Comtech EF Data HPCST-5000 - Manual (Page 68)

Single Thread System Installation High-Power TWTA Satellite Terminals
2–22 Rev.1
•
Fan ON (Pin M). (Active = low.)
When active, indicates that the amplifier’s main cooling fan is on when
Pin M (+) is connected by open collector to ground (Pin W). The main cooling
fan is controlled by the temperature of the TWT. The fan will cycle on and off in
cooler ambient conditions. The fan is typically operated below the
manufacturer’s nominal design voltage.
• High Voltage Fault (Pin R). (Active = low.)
When active, indicates there is a high voltage fault within the amplifier when
Pin R (+) is connected by open collector to ground (Pin W). A high voltage fault
is typically an indication of a serious power supply failure.
• Summary Fault (Pin T). (Active = low.)
When active, indicates there is a fault within the amplifier when Pin T (+) is
connected by open collector to ground (Pin W).
•
Fan Lock (Pin U). (Active = low.)
When active, indicates that the fan is locked when Pin U (+) is connected by
open collector to ground (Pin W). A Fan Lock signal is caused by fan failure or
an object interfering with fan rotation.
•
Control/Status Return (Pin W).
Common return.
•
External Fault (Pin S). (Active = high.)
When active, indicates there is a fault within the amplifier. Pin S opens (open
collector) to high impedance.