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

EN Environment Commands 6-3
User Default EnvironmentThis environment contains the
values that are set using the DEFAULT command or the
control panel keys. These values are stored in non-volatile
RAM (in those printers containing NVRAM). Following any PJL
reset condition, these values are placed into the PJL Current
Environment. If the printer has a control panel, the User
Default values are displayed on the control panel under the
appropriate menu.
PJL Current Environment This environment contains the
current PJL feature settings. Current settings are based on the
User Default values and any settings modified using the SET
command. These values default to the User Default values
when a PJL reset condition occurs.
Modified Print Environment This environment is active as
soon as a printer language is entered. At that time, the PJL
Current Environment values are loaded into the Modified Print
Environment and act as a base set of features. Printer
language commands then are used to modify feature settings
to the desired state. The PJL Current Environment settings are
loaded into the Modified Print Environment whenever a
personality is activated or a reset is received, including any
printer language reset or PJL reset condition.
Figure 6-1 illustrates how the environments interact, and how they
affect the modified print environment.