Connector Pinouts - Comtech EF Data SDM-100A Installation And Operation Manual

SDM-100A Satellite Modem
Fault indicators are also provided on TTL open collector drivers on the RS-422
connector.
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4.4.1.1 Connector Pinouts

The RS-422 interface is provided on a 37-pin female D connector accessible from the
rear panel of the modem. Screw locks are provided for mechanical security of the mating
connector.
Send Data
Send Timing
Receive Data
Request To Send
Receiver Timing
Clear To Send
Data Mode
Receiver Ready
Terminal Timing
Master Clock (Input)
Demod Fault
Mod Fault
Signal Ground
Note: The Request to Send (RTS) line is hard-wired to the Clear to Send (CTS) line
by JP11, pins 5 and 6, on the Demodulator/M&C card (AS/4973), since the modem
does not support polled operation.
Rev. 0
The TTL MOD fault indicates one of the following:
MODULATOR fault
COMMON EQUIPMENT fault
The TTL DEMOD fault indicates one of the following:
DEMOD fault
COMMON EQUIPMENT fault
Signal Function Name Pin #
SD-A 4
SD-B 22
ST-A 5
ST-B 23
RD-A 6
RD-B 24
RS-A 7
(See note below)
RS-B 25
(See note below)
RT-A 8
RT-B 26
CS-A 9
(See note below)
CS-B 27
(See note below)
DM-A 11
DM-B 29
RR-A 13
RR-B 31
TT-A 17
TT-B 35
MC-A 16
MC-B 34
— 21
— 3
SG 1, 19, 20, 37
Theory of Operation
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