本转换口把一个 25 针的串行设备接到 9 针的串行口上，PC 一侧为 9 针母插头：
到串行设备一侧为 25 针公插头：
|
引脚定义 |
|
|
9-Pin |
25-Pin |
|---|---|---|
|
Carrier Detect |
1 |
8 |
|
Receive Data |
2 |
3 |
|
Transmit Data |
3 |
2 |
|
Data Terminal Ready |
4 |
20 |
|
System Ground |
5 |
7 |
|
Data Set Ready |
6 |
6 |
|
Request to Send |
7 |
4 |
|
Clear to Send |
8 |
5 |
|
Ring InDICator |
9 |
22 |
