Hp Laserjet 4000 Series Comments - HP Color LaserJet 5500 Technical Reference Manual

HP LaserJet 4000
Series Comments
I/O Buffer Variables
The LaserJet 4000 series printers have a PJL feature set
similar to the LaserJet 5Si/5SiMx printers. Listed below
are some of the differences between the printers.
In addition to the LaserJet 5Si/5SiMx printer features, the
LaserJet 4000 series printers have:
1200 dpi print resolution
Support for the Czechoslovakian, Hungarian, and
Russian languages
Support for slightly different paper sizes
More Resolution Enhancement technology (REt) settings
Support for the CLEARABLEWARNINGS, COURIER,
MPTRAY, REPRINT, and WIDEA4 environment
variables
Reconfiguring the size of the LaserJet 4000 series I/O
buffers via the data stream can be difficult. The user may
try to send data to the printer while the I/O buffers are
being reconfigured, which results in the data being
consumed until the reconfiguration is complete. While it is
not anticipated that these commands will be used often, it
is expected that they will be used at least occasionally. For
this reason, a special communication sequence has been
proposed between the printer and this software, so that the
I/O buffers may be reconfigured via the data stream
without I/O being lost.
The following sequence assumes that the printer is idle.
Any I/O being sent by other users will be lost.
1. The software sends the job which includes a PJL com-
mand changing the configuration of the I/O buffers.
2. The software also sends an @PJL ECHO command at the
end of the job, followed by a UEL command.
3. The printer sends the echo command back to the host.
4. After the end of the job, the printer goes offline and recon-
figures the I/O buffers.
Feature Support A-43