9 Pin Serial Port Connector 9 pin "D" connector
Connector may be reversed depending on which side is viewed. All pins are numbered.
Pin No.	Function	Pin No.	Function
1	DCD (Data Carrier Detect)	6	DSR (Data Set Ready)
2	RX (Receive Data)	7	RTS (Request To Send)
3	TX (Transmit Data)	8	CTS (Clear To Send)
4	DTR (Data Terminal Ready)	9	RI (Ring Indicator)
5	GND (Signal Ground)