Skip to main content

RS-232

· One min read

Ref: Wikipedia

RS-232 / COM port / Serial port

Connector​

  • DB-25
  • DE-9 (AKA DB-9)
  • Usually use DE-9
  • DTE (male)
  • DCE (female)

DE-9​

DE-9 is correct name, but usually name DB-9

Ref: D-subminiature

Pin​

PinSIGNameDTE (male)
1DCDData Carrier Detectin
2RXDReceive Datain
3TXDTransmit Dataout
4DTRData Terminal Readyout
5GNDSignal Ground-
6DSRData Set Readyin
7RTSRequest To Sendout
8CTSClear To Sendin
9RIRing Indicatorin

DB-9 pinout

Common usage​

RXD TXD GND