Comtech EF Data SDM-300A - Manual (Page 56)

SDM-300A Satellite Modem Revision 6
Functional Description MN/SDM300A.IOM
2–16
A backward alarm being received on a particular link is detected by one of the two following
methods:
• The backward alarm output drives a FORM C relay with all three contacts available on
the data connector.
• The status of all transmit and receive backward alarms may be read through the RS-232
or RS-485 remote interface connector that is integrating a modem or switch into a
computer network.
In addition to the four backward alarms for IDR and two backward alarms (primary and
secondary) for IBS, all modes support the following faults:
• MOD (modulator equipment)
• DEM (demodulator equipment)
• CEQ (common equipment)
Each fault is indicated by a FORM C relay contact and an open collector output.