Rs-232C Interface; Print Speed And Timing - NCR 7158 Owner's Manual

RS-232C Interface

Print Speed and Timing

The RS-232C interface uses either the XON/XOFF (software) or
DTR/DSR (hardware) protocol to control the flow of information
between the computer and the printer. For XON/XOFF, a particular
character is sent back and forth between the host and the printer to
regulate the communication. For DTR/DSR, changes in the DTR/DSR
signal on the RS 232 interface coordinate the information flow.
The RS-232C interface offers standard settings that are selected with
the Configuration Menu. Use of the Configuration Menu is described
in "Configuring the Printer" in this manual.
The fast speed of the printer requires the application to send data to the
printer at least as fast as it is printed. The application must also allow
output lines to be buffered ahead at the printer, so the printer will be
able to print each line immediately after the preceding line, without
stopping to wait for more data. Ideally, the application will send all the
data for an entire receipt or slip without pausing between characters or
lines transmitted.
Chapter 6: Communication Interface 6-3