TM 11-7025-234-23
Interface Signal Descriptions
E IA
CCITT
RS-232C
V.24
J1
Signal Name
Description
101
1 Protective Ground or
Chassis ground. Isolated from
AA
E art h
signal ground or common return
(AB, pin 7).
Common signal and dc power ground.
7 Signal Ground or
AB
102
Isolated from Protective Ground
Common Return
(AA, pin 1).
Serial digital data from a data
2 Transmitted Data
103
BA
terminal or other digital data
source accompanied by DB. If
accompanied by an external data
rate clock (DA), data transitions
must occur on positive going
transitions of the external
transmit input clock.
Serial digital data at the output
104
3 Received Data
BB
of the modem receiver. The data
is accompanied by an internal data
rate clock (DD) whose positive
going transitions occur on the
data transitions.
A positive level to the modem when
4 Request to Send
105
CA
data transmission is desired.
A positive level from the modem
106
5 Clear to Send
CB
with a selectable delay, after
receipt of Request to Send (CA)
and when the modem is ready to
transmit. Clear to Send is low
during training or when Request to
Send is low.
cc
A positive level from the modem
107
6 Data Set Ready
when power is on and not in the
Test mode.
A positive level from the modem
109
8 Received Line Signal
CF
Detector
except when a loss of the received
input signal is detected (carrier
detect).
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A positive level or pulse will
11 Remote Digital Loopback
cause a digital loopback at a
remote modem in modems with a
Remote Loopback option.
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