Control Panel Menus 3-27 
PARALLEL HIGH
SPEED=YES
YES
NO
Select the speed at which data is transmitted to 
the printer.
YES
: The printer accepts faster parallel 
communications used for connections with 
newer computers.
NO
: The printer accepts slower parallel 
communications used for connections with older 
computers.
PARALLEL ADV
FUNCTIONS=ON
ON
OFF
Turn the bidirectional parallel communication on 
or off. The default is set for a bidirectional 
parallel port (IEEE-1284).
This setting allows the printer to send status 
readback messages to the computer. (Turning 
on the parallel advanced functions might slow 
language switching.)
SERIAL 
PACING=DTR/DSR
DTR/DSR
XON/XOFF
Select the type of pacing used. Pacing, or 
“handshaking” allows the printer to tell the 
computer when to send information. The printer 
uses XON/XOFF and DTR/DSR signal protocols 
rather than ETX/ACK protocol. 
DTR/DSR
: Select this value if your computer 
requires hardware flow control (most personal 
computers do). 
XON/XOFF
: Select this value if your computer 
requires software flow control (a UNIX 
workstation, for example). The 
SERIAL 
ROBUST XON 
item appears (see below). 
Table 3-11. I/O Menu (continued)
Item Values Explanation
For more information on the LaserJet 4000 / 4050 Visit www.PrinterSupplies.com 800-551-1943