Comtech EF Data SMS-758 - Manual (Page 73)

SMS-758 Modem Protection Switch Theory of Operation
MN/SMS758 Rev. 3 4–13
4.6.1.2 Connector Pinouts
A 37-pin female D connector provides interface for the RS-422/449 and
MIL-STD-188-114/RS-449 interface.
Screw locks provide mechanical security for the mating connector.
Signal Function Name Pin #
Signal Ground SG 1,19,20,37
Send Data SD-A 4
SD-B 22
Send Timing ST-A 5
ST-B 23
Receive Data RD-A 6
RD-B 24
Request To Send RS-A 7
RS-B 25
Receiver Timing RT-A 8
RT-B 26
Clear To Send CS-A 9
CS-B 27
Data Mode DM-A 11
DM-B 29
Receiver Ready RR-A 13
RR-B 31
Terminal Timing TT-A 17
TT-B 35
Master Clock MC-A 16
MC-B 34
Modulator Fault MF 3
Demodulator Fault DF 21
Note: MF and DF inputs are only on the prime and backup modem interface connectors,
not the terrestrial data connector.