HP PCL/PJL reference - Printer Job Language Technical Reference Manual

EN Kernel Commands 4-1
4
Kernel Commands
Introduction
This chapter explains the following three PJL commands:
• Universal Exit Language (UEL) command — exits the current
printer language and returns control to PJL.
•ENTER command — selects a printer language for processing
the current job.
• COMMENT command — enables developers to add
comments to their PJL commands.
Together, these commands provide a minimum set of tools necessary
to implement job control. These commands allow applications to set
job boundaries, add comments, and programmatically select printer
languages.
Besides programmatic printer language switching, you can configure
some LaserJet printers to switch printer languages automatically
between print jobs. Following the descriptions of the UEL, ENTER,
and COMMENT commands, this chapter describes the different
methods used to switch printer languages.
Note For information about products newer than those included in this
book, see the Printer Job Language Technical Reference Addendum,
which includes product-specific information about newer products, as
well as commands and variables added to PJL to support these
newer products.