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|
|4||DTR||Data Terminal Ready||Out|
|6||DSR||Data Set Ready||In|
|7||RTS||Request to Send||Out|
|8||CTS||Clear to Send||In|