EIA-232-D Pin Assignments
Table E-3 lists the EIA-232-D pin assignments for the
modem.
RS-232
EIA
Name
Pin
Circuit
1
—
AA
2
TXD
BA
3
RXD
BB
4
RTS
CA
5
CTS
CB
6
DSR
CC
7
SG
AB
8
LSD
CF
9
+10V
—
10
–10V
—
11
—
—
12
CT112
CI
13
—
—
14
—
—
15
TXC
DB
16
—
—
17
RXC
DD
18
CT141
LL
20
DTR
CD
21
CT140
RL
22
RI
CE
23
CT111
CH
24
XTXC
DA
25
TEST
TM
3810-A2-GB30-30
Table E-3
EIA-232-D Pin Assignments
Signal
ITU-T
Source
101
—
Shield
103
DTE
Transmit Data
104
DCE
Receive Data
105
DTE
Request-to-Send
106
DCE
Clear-to-Send
107
DCE
Data Set Ready
102
—
Signal Ground
109
DCE
Line Signal Detect
—
—
Reserved for test purposes (may be used to drive one RS-232
load)
—
—
Reserved for test purposes (may be used to drive one RS-232
load)
—
—
Unassigned
112
DCE
Data Signal Rate Select
—
—
Reserved for future function
—
—
Reserved for future function
114
DCE
Transmit Clock
—
—
Reserved for future function
115
DCE
Receive Clock
141
DTE
Local Loopback
108
DTE
Data Terminal Ready
140
DTE
Remote Loopback
125
DCE
Ring Indicator
111
DTE
Data Rate Selector
113
DTE
External Clock
142
DCE
Test Mode
September 1998
Circuit Function
Pin Assignments
E-3