Xerox WorkCentre Pro 423 Service Manual

Also see for WorkCentre Pro 423: Scanner guide Fax guide Brochure & specs Fax guide User guide

WorkCentre Pro 423/428 2-106 CHAPTER 2 TROUBLESHOOTING03/02 Level 2 Troubleshooting2.3.3 Super G3 Fax2.3.3.1 Super G3 FaxIn 1996, ITU-T recommended Super G3 Fax.Super G3 Fax featuring 28.8 kbps communication has the modem capabilities of V.8 andV.34. The protocol consists of V.8 and V.34 and optionally supports 33.6 kbps. Super G3 Faxenables a fax to communicate with models of other manufacturers and also with theconventional 14.4 kbps and 9600 bps faxes.l Super G3 Fax communication is recorded as SG3 in the mode column of a report.l Super G3 Fax transmits image information in Error Correction Mode (ECM).l V.34 is a standard for modems from 28.8 kbps (optionally, 33.6 kbps) to 2400 bps.Prior to the V.34 standard, V.8 prescribes a procedure for selecting optimum modeaccording to the line status.For communication with the conventional faxes as well as V.34 (28.8 kbps) ones, Super G3Fax has also the capabilities of V.17 (14.4 kbps) and V.29/V.27ter (9600/4800 bps). The V.8standard prescribes a procedure for checking the line status and selecting an optimum speed.l V.34 does not use the TCF signal in phase B.l In V.34, the command (NSF, DIS, and other) speed for the conventional proceduresection is 1200 bps.Signal names and contentsDialTerminationCalling (CNG) signal: To indicate a communication function,the local terminal sends this signal continuously until theANSam signal is received. This signal is not recorded in tracedata.For manual transmission, a terminal sends "CI" as the V.8calling signal.Also if the protocol enters phase B without detecting ANSamand DIS V.8 capability is enabled (bit 6=1), the originationside sends CI and returns to the V.8 procedure in Super G3mode.ANSam (response signal): The fax stops after sending a 2100Hz signal modulated by 15 Hz for 4 continuous seconds orwhen CM is detected. If the fax does not support Super G3mode, CED is detected.Call menu (CM) signal: This 300 bps signal (*) declaresmodem mode available at the local terminal.Common menu (JM) signal: This 300 bps signal (*) declaresmodem mode available at the local and remote terminals andstops when CJ is detected. (For the FIFs of the CM and JMsignals, see No.2 "V.8 CM/JM Signal.")CM end (CJ) signal: This 300 bps signal indicating JM checkand CM end is a three-octet string of 0.[V34ph2][V34ph3][V34ph4]V.34 Phase 2 (ph2): ProbingThe line characteristics are measured using the probingsignal.V.34 Phase 3 (ph3): Equalizer trainingThe modem equalizer is set using the TRN signal.V.34 Phase 4 (ph4): Final trainingThe signal speed is determined.(V.34 Phase 1 means the V.8 procedure.)The modems of the local and remote terminals automaticallyexecute this section (Phases 2 to 4) to determine the sendlevel, equalizer, and modulation speed. The valuesdetermined here have priority over the NSF/DIS contents.NSFDISNSSCFRTRNTRNCPIXCPIXPPS.EOPMCFDCNLOCAL REMOTECNG ANSamCM JMCJV.8V.34Phase BSample Protocol (T.30) Trace of Super G3 FaxThe V.34 modem has a command channel (low-speed channel for NSF, DIS, and othercommands) and a primary channel (high-speedchannel for image and training signals).Phase CPhase D*Phases B to E belong to the facsimileprocedure.Phase E