NCR 74 OFX (7874) - Handshake; Stop Bits and Character Length

5-44 Chapter 5: Programming
Stop Bits and Character Length
TheStopBitsandCharacterLengthparametercontainsfourselections:1StopBitand
7‐bitCharacterLength,1StopBitand8‐bitCharacterLength,2StopBitsand7‐bit
CharacterLength,and2StopBitsand8‐bitCharacterLength.Choosingnoparityand
7‐bitCharacterLength
causestheRealScan74tosendtwo(2)stopbits;thescanner
mustalsoreceivetwo(2)stopbits.If8‐bitCharacterlengthandparityisselected,only
one(1)stopbitissent.ScantheappropriateHex0throughHex3tagtosettheStop
Bitsand
CharacterLength.
Handshake
TheHandshakeparametercontainssixselections.Whenconsideringthese,notethat
thescannercontrolsonlyRTS;however,itcanmonitorCTS.Thefollowinglist
identifieseachHandshakeoption.
•
RTSisalwayslow,CTSisignored(Hex0tag).
•
RTSisalwayshigh,CTSisignored(Hex1tag).
•
ScannerraisesRTSandwaitsforCTStogohighbeforetransmitting(Hex2tag).
•
ScannerraisesRTSbeforetransmittingandignoresthestateofCTS(Hex3tag).
•
RTSisalwayslowandscannerwaitsforCTStogohighbeforetransmitting(Hex
4tag).
•
RTSisalwayshighandscannerwaitsforCTStogohighbeforetransmitting(Hex
5tag).
ScantheappropriateHex0throughHex5tagtosettheHandshakeoption.