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 |
