RS 232 Pinouts for DB25 and DB9 Connectors
Pins commonly used for RS-232 (serial):
|
DB-25 |
DB-9 |
Signal Direction |
Signal Name |
|---|---|---|---|
|
1 |
x |
Protective |
Ground |
|
2 |
3 |
DTE-to-DCE |
Transmitted Data |
|
3 |
2 |
DCE-to-DTE |
Received Data |
|
4 |
7 |
DTE-to-DCE |
Request To Send |
|
5 |
8 |
DCE-to-DTE |
Clear To Send |
|
6 |
6 |
DCE-to-DTE |
Data Set Ready |
|
7 |
5 |
x |
Signal Ground |
|
8 |
1 |
DCE-to-DTE |
Received Line Signal Detector (Carrier Detect) |
|
20 |
4 |
DTE-to-DCE |
Data Terminal Ready |
|
22 |
9 |
DCE-to-DTE |
Ring Indicator |
Commonly used RS232 Null Modem Pin out for DB25 and DB 9 connectors:
|
Signal |
Name |
DB-25 |
DB-9 |
DB-9 | DB-25 | Signal | |
|---|---|---|---|---|---|---|---|
|
FG |
(Frame Ground) |
1 |
- |
<-> |
- |
1 |
FG |
|
TD |
(Transmit Data) |
2 |
3 |
2 |
3 |
RD |
|
|
RD |
(Receive Data) |
3 |
2 |
3 |
2 |
TD |
|
|
RTS |
(Request To Send) |
4 |
7 |
8 |
5 |
CTS |
|
|
CTS |
(Clear To Send) |
5 |
8 |
7 |
4 |
RTS |
|
|
SG |
(Signal Ground) |
7 |
5 |
5 |
7 |
SG |
|
|
DSR |
(Data Set Ready) |
6 |
6 |
4 |
20 |
DTR |
|
|
CD |
(Carrier Detect) |
8 |
1 |
4 |
20 |
DTR |
|
|
DTR |
(Data Terminal Ready) |
20 |
4 |
1 |
8 |
CD |
|
|
DTR |
(Data Terminal Ready) |
20 |
4 |
6 |
6 |
DSR |