DB9 Pinout

Pinout

The pins below are found on a typical male (terminal side, or DTE) DB-9 serial port connector:

Pin Signal Direction Description
1 DCD IN Carrier Detect
2 RXD IN Receive Data
3 TXD OUT Transmit Data
4 DTR OUT Data Terminal Ready
5 GND - Signal Ground
6 DSR IN Data Set Ready
7 RTS OUT Request To Send
8 CTS IN Clear To Send
9 RI IN Ring Indicator