DB-9 Connector Pinout
The DB-9 connector is a member of the D-subminiature or D-sub family of connectors and is officially known as the DE-9 connector. It is commonly used for RS232 serial ports.
Note that the DTE device (eg the PC) uses the male plug and the DCE peripheral (eg the modem) uses the female socket.
|1||DCD||Data Carrier Detect|
|4||DTR||Data Terminal Ready|
|6||DSR||Data Set Ready|
|7||RTS||Request to Send|
|8||CTS||Clear to Send|
- The DCE peripheral receives data on the TXD line and transmits on the RXD line.
- For a null-modem connection, DTR is connected to DSR and RTS is connected to CTS.