
7156 Owner’s Guide
Chapter 5: Communication
September 1997
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0.44 Seconds
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2.4 Seconds
XON/XOFF Protocol
The XON/XOFF characters coordinate the information transfer between the printer and
the host computer. The printer sends an XON character when it is ready to receive data
and it sends an XOFF character when it cannot accept any more data. The software on the
host computer must monitor the communication link as shown in the following flowchart
in order to send data at the appropriate times.
If XON/XOFF has been selected, the printer also toggles the DTR signal, as described in
the next section, but it does not look at the DSR signal to transmit data.
XON character = Hex 11.
XOFF character = Hex 13.
DTR/DSR Protocol
The DTR signal is used to control data transmission to the printer. It is driven low when
the printer is ready to recieve data and driven high when it cannot accept any more data.
Data is transmitted from the printer after it confirms that the DSR signal is low.
Содержание 7156
Страница 1: ...BD20 1436 A Issue B September 1997 NCR 7156 Thermal Receipt and Impact Slip RS232 Owner s Guide...
Страница 6: ...Contents 7156 Owner s Guide September 1997 iv...
Страница 31: ...7156 Owner s Guide Chapter 2 Setting Up and Using the Printer September 1997 25 Sample Print Test...
Страница 38: ...Chapter 3 Solving Problems 7156 Owner s Guide September 1997 32...
Страница 118: ...Chapter 6 Commands 7156 Owner s Guide September 1997 112...
Страница 122: ...Appendix A Specifications 7156 Owner s Guide September 1997 116...
Страница 129: ...7156 Owner s Guide Appendix B Print Characteristics September 1997 123...
Страница 130: ...Appendix B Print Characteristics 7156 Owner s Guide September 1997 124...
Страница 136: ...Index 7156 Owner s Guide September 1997 6...