2.8 TERMINAL CONNECTIONInstallation Manual 61Standard IBM 25-Pin Connection2.8.3 RS-232C SignalsFrame Ground (FG)Connects an external ground to the unit frame, usually the ground pin of the AC powercord.Transmitted Data (TXD)—outputConveys signals from the unit to the terminal/printer. A "mark" condition is held unlessdata or BREAK signals are being transmitted.Received Data (RXD)—inputConveys signals from the terminal/printer to the unit.Request To Send (RTS)—outputThis lead is held on whenever DSR is on.Signal Ground (SG)Connects to the DC ground of the unit for all interface signals.Data Terminal Ready (DTR)—outputThis signal line is turned on by the unit to indicate that it is RS-232C on-line. Circuit DTRON does not indicate that communication has been established with the terminal/printer.It is switched off when the unit is RS-232C off-line.Table 2-8 Pin Configuration of the RS-232CPinNumber Signal Name Circuit TypeRS-232C CCITT12FGTXDFrame GroundTransmitted DataAABA10110334RXDRTSReceived DataRequest To SendBBCA1041056 DSR Data Set Ready CC 10778SGDCDSignal GroundData Carrier DetectABCF10210920 DTR Data Terminal Ready CD 108.2®Circuit Type(RS-232C)AABABBABCDCircuit Type(RS-232C)AABABBABCDSignalNameFGTXDRXDSGDTRSignalNameFGTXDRXDSGDTRPin No.123720Pin No.1237CBCTS5CCDSR6CFDCD820
