RS422串行口针脚定义图 引脚定义计算机侧 RS-422 串行接口的插口是 25 针公插：设备侧 RS-422 串行接口插头是 25 针母插： 引脚定义PinNameDirDescription1GNDShield Ground2SRISignal Rate Indicator3n/c-Spare4SDSend Data5STSend Timing6RDReceive Data7RTSRequest To Send8RRReceiver Ready9CTSClear To Send10LLLocal Loopback11DMData Modem12TRTerminal Ready13RRReceiver Ready14RLRemote Loopback15ICIncoming Call16SF/SRSelect Frequency/Select Rate17TTTerminal Timing18TMTest Mode19GNDGround20RCReceive Twister-Pair Common21GNDSpare Twister-Pair Return22/SDSend Data TPR23GNDSend Timing TPR24GNDReceive Timing TPR25/RSRequest To Send TPR26/RTReceive Timing TPR27/CSClear To Send TPR28ISTerminal In Service29/DMData Mode TPR30/TRTerminal Ready TPR31/RRReceiver TPR32SSSelect Standby33SQSignal Quality34NSNew Signal35/TTTerminal Timing TPR36SBStandby Indicator37SCSend Twister Pair Common