Common names:
EIA-232D (RS232-D), ITU-TSS (CCITT) V.24/V.28, ISO 2110
(at
the DTE)
(at
the DCE)
25 PIN D-SUB MALE
at the DTE (Computer).
25 PIN D-SUB FEMALE at the DCE (Modem).
Pin |
Name |
RS232 |
V.24 |
Dir |
Description |
1 |
GND |
n/a |
101 |
|
Shield
Ground |
2 |
TXD |
BA |
103 |
|
Transmit
Data |
3 |
RXD |
BB |
104 |
|
Receive
Data |
4 |
RTS |
CA |
105 |
|
Request
to Send |
5 |
CTS |
CB |
106 |
|
Clear
to Send |
6 |
DSR |
CC |
107 |
|
Data
Set Ready |
7 |
GND |
AB |
102 |
|
System
Ground |
8 |
CD |
CF |
109 |
|
Carrier
Detect |
9 |
- |
|
|
- |
RESERVED |
10 |
- |
|
|
- |
RESERVED |
11 |
STF |
|
126 |
|
Select
Transmit Channel |
12 |
S.CD |
SCF |
122 |
|
Secondary
Carrier Detect |
13 |
S.CTS |
SCB |
121 |
|
Secondary
Clear to Send |
14 |
S.TXD |
SBA |
118 |
|
Secondary
Transmit Data |
15 |
TCK |
DB |
114 |
|
Transmission
Signal Element Timing |
16 |
S.RXD |
SBB |
119 |
|
Secondary
Receive Data |
17 |
RCK |
DD |
115 |
|
Receiver
Signal Element Timing |
18 |
LL |
LL |
141 |
|
Local
Loop Control |
19 |
S.RTS |
SCA |
120 |
|
Secondary
Request to Send |
20 |
DTR |
CD |
108.2 |
|
Data
Terminal Ready |
21 |
RL |
RL |
140 |
|
Remote
Loop Control |
22 |
RI |
CE |
125 |
|
Ring
Indicator |
23 |
DSR |
CH |
111 |
|
Data
Signal Rate Selector |
24 |
XCK |
DA |
113 |
|
Transmit
Signal Element Timing |
25 |
TI |
TM |
142 |
|
Test
Indicator |
Note: Direction is DTE
(Computer) relative DCE (Modem).
Note: RS232 column is RS232 circuit name.
Note: ITU-T column is ITU-TSS V.24 circuit name.
Note: Do not connect SHIELD(1) to GND(7).
|