串行直连电缆用于两台台电脑通过串行口直接相连，电缆两端的插头都是9 针的母插头：
|
两台电脑串行通信直连对接方法引脚定义 |
通过此表可以看出两台电脑通过串口直接连接传输数据的接线方法：
|
|
D-Sub 1 |
D-Sub 2 |
|
|---|---|---|---|
|
Receive Data |
2 |
3 |
Transmit Data |
|
Transmit Data |
3 |
2 |
Receive Data |
|
Data Terminal Ready |
4 |
6+1 |
Data Set Ready + Carrier Detect |
|
System Ground |
5 |
5 |
System Ground |
|
Data Set Ready + Carrier Detect |
6+1 |
4 |
Data Terminal Ready |
|
Request to Send |
7 |
8 |
Clear to Send |
|
Clear to Send |
8 |
7 |
Request to Send |