RS232 Serial Port Pinout

RS232 9-Pin Functions of the Female End Connector
The following table explains the pin functions for the female DCE DE-9 connector.

Note: The DSR signal on pin 6 is always asserted.

The DE-9 is configured as a DCE (Data Communications Equipment) interface. To use the MultiConnect OCG-D as a DTE (Data Terminal Equipment), then the use of a null modem cable/adapter is needed. A DTE device can be thought of as being like a PC whereas a DCE device would be like a modem.