计算机端9 pin (DS9)定义如下:
Pin Name Dir Description
1 CD In Carrier Detect
2 RXD In Receive Data
3 TXD Out Transmit Data
4 DTR Out Data Terminal Ready
5 GND --- System Ground
6 DSR In Data Set Ready
7 RTS Out Request to Send
8 CTS In Clear to Send
9 RI In Ring Indicator