RS232 Pinout

Below is the pinout of a typical standard male 9-pin RS232 connector, this connector type is also referred to as a DB9 connector.
A computer's serial COM port (DTE) is usually a male port as shown below, and any peripheral devices you connect to this port usually has a female connector (DCE).

This table shows the pin numbers with signal names and the signal direction.

Pin	Signal	Signal Name	DTE Signal direction
1	DCD	Data Carrier Detect	In
2	RXD	Receive Data	In
3	TXD	Transmit Data	Out
4	DTR	Data Terminal Ready	Out
5	GND	Ground	-
6	DSR	Data Set Ready	In
7	RTS	Request to Send	Out
8	CTS	Clear to Send	In
9	RI	Ring Indicator	In