Lexmark Printer User Manual page 369

Protocol (RS-232C)
Table 8-5 shows the state or function of each serial interface signal in the three data
flow control protocols when the Honor DSR setting is On.
Table 8-5: Serial Link (All Protocols) with Honor DSR On
Printer
DTR
DSR
CTS
Table 8-6 shows the state of each serial interface signal in the three data flow control
protocols when the Honor DSR setting is Off.
Table 8-6: Serial Link (All Protocols) with Honor DSR Off
Printer Signal
DTR (Output)
DSR (Input)
CTS (Input)
1
These values are compatible with Hewlett-Packard Company's LaserJet printers.
XON/XOFF Protocol DTR Protocol
(Honor DSR On) (Honor DSR On)
Always active Flow control to computer
Data validity Data validity
Ignored Flow control from computer
XON/XOFF Protocol
(Honor DSR Off)
Always active
Ignored
Ignored
8-32
DTR/DSR Protocol
(Honor DSR On)
Flow control to
computer
Flow control (transmit
mode) to computer
(receive mode)
Ignored
DTR Protocol DTR/DSR Protocol
(Honor DSR Off) (Honor DSR Off)
Flow control to Flow control to computer
computer
1
Ignored Flow control to computer
Flow control from Ignored
1
computer
Interfaces