meric characters. This can enable the name of the 14.4kbit/s maximum rate on a 64kbit/s channel. communicating machine to be shown on the display or recorded in Clearly where 64kbit/s digital access is available, as through the the activity report. It is not recognised between machines of differ- ISDN connection, a direct digital input at 64kbit/s machine data rate ent manufacturers. is desirable giving an improvement of four to six times in speed and 64kbit/s facsimile equipment 60/13 Transmitter Receiver (Auto reception) Table 60.8 Popular G3 handshake signals Dialing Ringer detection CNG 1100Hz Line seize Abbreviation Function Called station identification Confirmation to receive NSF-CSI-DIS (Note) Calling subscriber identification TSI-DCS/NSS (Note) NSS is transmitted if the receiver is of a same Calling tone Modem training manufacturer. Called subscriber identification Disconnect Digital command signal Image Digital identification signal Digital transmit command Next page present End of message Next page feed in End of procedure Image Response for end of retransmission Facsimile coded date Next page absent Facsimile control field Frame checking sequence Line release Facsimile information field Line release Failure to train High level data link control Message confirmation Figure 60.7 Typical G3 signal flow chart Multi-page signal Non-standard facilities reduction in transmission cost. To take advantage of this a 64kbit/s data rate facsimile machine is required. Non-standard set-up Partial page signal 60.5.1 G4 equipment Partial page request CCITT has produced recommendations for G4 digital equipment in Return to control for partial page 3 classes based on the ISO 7 layer model for interoperation with Receive not ready open systems communication standards. Receive ready Class 1 is for the transmission of facsimile documents only and is a higher performance equivalent to G3. Class 2 has the transmission Return to control capabilities of Class 1 and the receive capabilities of class 3. It is Retrain negative si