Plain paper printers receiver answers the ringing current by sending a DIS to indicate its capabilities. These includes the paper size, coding schemes and A number of technologies are available to produce the printed image modem rates it has available. on plain, office type paper. The advantages of this is that copies feel The transmit machine selects appropriate conditions in conjunc- like other office documents and are generally archival. tion with document size and operator selections, commands the receiver using DCS and sends the modem training signal and TCF Thermal Transfer at the high speed data rate. The receiver attempts to train, checks the performance on TCF The paper is usually in roll form to simplify machine handling. It and replies either CFR or FTT. The transmitter then either starts the moves through the machine with, and generally at the same rate, as image transmission or sends DCS and training again. a thermal transfer film. The thermal head prints in a similar way to Figure 60.7 shows a typical G3 signal flow chart, and Table 60.8 normal thermal paper printing and the film is a donor, transferring gives popular G3 handshake signals. its image to the plain paper. The thermal transfer film, collected on When the transmitter indicates the end of page the receiver replies a take up roll, is used at the same rate as the paper and retains a with MCF for a correctly received page, or one of the retrain signals negative image which may need careful handling for security rea- indicating that it requires retraining for any further pages. sons. If the transmitter signalled MPS, advising more pages to be sent, The facsimile printer is otherwise identical to a thermal paper it continues with the following pages, finishing with EOP and DCN printer. in response to MCF before releasing the connection. Electrophotographic 60.4.6.2 G3 machine identification A well established technology in office printers uses either a laser or an LED array to discharge a photoconductive drum for offset Identification of termi