Comtech EF Data SDM-9000 - Manual (Page 157)

SDM-9000 Satellite Modem Theory of Operation
Rev.4 5–29
More complicated systems may be handled by connecting the appropriate outputs of the
receive fault relay to the appropriate backward alarm inputs. In a multidestination
system, the relay might only be connected to the particular backward alarm assigned to
that link. Refer to IESS-308 for further clarification.
There are two methods for detecting a backward alarm that is being received on a
particular link:
• Each backward alarm output drives a Form C relay with all three contacts
available on the data connector.
• If a modem (or switch) is integrated into a computer network through the modem
(or switch) RS-232-C or RS-485 remote interface connector, the status of all transmit and
receive backward alarms may be read through that port.
Refer to Appendix B for remote control operation information.