Description

D sub 9 pin connector:

D sub 9 pin connector/DB9 connectors have been a common serial port connection for decades. Nine positions are available for data transfer and the shell automatically grounds to the chassis. These nine pin connectors come in vertical or right-angle orientations for top or side entry of cables. D-subs are available in a wide range of plating options to meet application cycles plus a wide range of mounting options for very secure connections.

 

The DB9  (originally named DE-9) is an analog socket, from the D-Subminiatures (D-Sub)  family. The DB9 has the smallest “footprint” of the D-Subminiature connectors. The prefix “D” represents the D-shape of the connector shell. The DB9 connector is mainly used in serial ports, allowing asynchronous data transmission according to the RS-232 standard (RS-232C). Note that there are DB9-DB25 adapters that easily convert a DB9 socket to DB25 and vice versa.

 

PIN Out of D-Sub 9 Pin Connector:

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