9 Pin Serial Pinouts
D-sub 9 Connector PinoutPinout and diagram of DE9 connector (DB9 connector), commonly used for serial ports (RS-232).PinSIG.Signal NameDTE (PC)1DCDData Carrier Detectin2RXDReceive Datain3TXDTransmit Dataout4DTRData Terminal Readyout5GNDSignal Ground-6DSRData Set Readyin7RTSRequest to Sendout8CTSClear to Sendin9RIRing IndicatorinThe DTE (PC) has the male connector (shown below), and the DCE (peripheral) has the female.RS-232 Maximum Cable LengthThe maximum cable length for RS-232 is 50ft, but in practise depends on baud rate, cable specific capacitance and ambient noise. The table below contains some rules-of-thumb from experiments done by Texas Instruments years ago.Baud rateMaximum range / cable length1920050ft9600500ft48001000ft24003000ftQuestions, comments info (at) (this domain)Other quick-reference sites:.