Comtech EF Data SDM-300A - Manual (Page 83)

SDM-300A Satellite Modem Revision 6
External Connections MN/SDM300A.IOM
4–5
4.1.2 Fault Connector and Pinouts (J7)
The fault connector provides Form C contact closures for fault reporting. The three Form C
summary fault contacts, ratings 1A maximum at 24 VDC, 0.5A at 120 VAC, are Modulator,
Demodulator, and Common Equipment.
The fault interface connection is a 9-pin subminiature female D connector (J7) located on the rear
panel of the modem. Screw locks are provided for mechanical security on the mating connector.
Refer to Table 4-3 for pinout information.
Table 4-3. Fault Connector and Pinouts (J7)
Pin # Signal Function Name
1 Common equipment is not faulted NO
2 COM
3 Common equipment is faulted NC
4 Modulator is not faulted NO
5 COM
6 Modulator is faulted NC
7 Demodulator is not faulted NO
8 COM
9 Demodulator is faulted NC
Note: A connection between the common (COM) and normally open (NO) contacts
indicates no fault.
To obtain a system summary fault, connect all the Form C contacts in parallel.