User Manual – Rev AY AMETEK Programmable PowerMX Series 64DB-9 PC DB-9 AC SourcePin123456789Pin123456789Directionoutputinputoutputoutput-input--outputDescriptionreservedReceive data(RxD)Transmit data (TxD)Data Terminal Ready (DTR)Signal GroundData Set Ready (DSR)no connectno connectreservedFigure 3-15: RS232C Cable for PC Connection wiring diagram – MX without USB.