Lexmark X422 Technical Reference Manual page 330

Data Flow Control
Data flow control is accomplished through the following lines:
•
Data Set Ready (DSR)
•
Data Terminal Ready (DTR)
Five data flow control protocols are available:
•
DTR pacing
•
DTR/DSR
•
XON/XOFF
•
XON/XOFF/DTR
•
XON/XOFF/DTR/DSR
Your printer supports two modes in which both hardware and software data flow
control protocols are performed. In XON/XOFF/DTR mode, the printer uses both
XON/XOFF and DTR pacing. When XON/XOFF/DTR/DSR mode is active, the printer
uses both XON/XOFF and DTR/DSR pacing.
Robust XON may be selected when the data flow control protocol for the serial port is
set to XON/XOFF, XON/XOFF/DTR, or XON/XOFF/DTR/DSR pacing. The printer
sends a continuous stream of XON signals to the host computer to indicate that the
serial port is ready to receive additional data. The signals continue as long as one of
the following conditions exist:
•
No data has been received across the serial port in the last second.
•
The last XON was accepted by the host computer.
•
The printer is ready to receive data.
Refer to your printer user documentation for more information about selecting the
protocol from the printer operator panel or through MarkVision Professional.
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Interfaces