Environment Variables; Accxes Environment Variable Organization; Parameter Classes; Parameter Groups - Xerox 850DP - Phaser Color Solid Ink Printer Manual

Version 10.0
AccXES PJL Interface

5 Environment Variables

5.1 AccXES Environment Variable Organization

The terms 'parameter,' 'class,' 'group,' and 'environment' are used to group the collection of printer
parameters and state variables functionally and by usage. Classes and groups are specific to the
AccXES architecture. They are used to categorize the set of AccXES environment variables in two
levels. This organization has no counterpart in HP-PJL. In HP-PJL, there is simply a flat set of
environment variables without subdivision. Parameter Environments is a concept taken directly from
the definition of HP-PJL. The sections below define these terms.
There is a one to one mapping of HP-PJL environment variables to the AccXES printer parameters for
almost all types of parameters. In many cases, even AccXES printer state variables such as ESSSTATE
have corresponding HP-PJL environment variables. State variables such as this may be queried for
their value, but they may not be set. Because of the close relationship between HP-PJL environment
variables and AccXES printer parameters, the words 'parameters' and 'environment variables' are used
interchangeably.

5.1.1 Parameter Classes

The parameters are divided into classes. Parameters collected in the same class pertain to the same
functional area within the printer. For example, the Communication Parameters Class collects all
parameters associated with the various host interfaces.
There are four classes in the AccXES architecture:
Communications Class. - The Communications class stores all parameters associated with the host
interface ports. Such parameters include serial baud rate, SCSI ID, etc.
Printer Class. - The Printer Class of parameters stores all parameters having to do with the printing
system as a whole. The language used by the user interface is an example of a Printer Class parameter.
Processing Class. - Processing Class parameters affect how job or page within a job is processed. An
example of this type of parameter might be the paper size required to print the job.
Printer State Class. - The Printer State Class of parameters records the state of the printer and
associated printing engine. There are three associated groups: marking engine, media, and ESS. Each
of these subsystems is responsible for manipulating the values of these states. To the rest of the
system, the variables in the Printer State Class are read-only.

5.1.2 Parameter Groups

Parameters are further sub-divided into logical sets called groups so that consistency checking can be
performed. Consistency checking is executed by specifying a function in the printer software
architecture capable of checking a proposed set of parameters to insure that the new combination is
indeed valid. If the parameter set is confirmed, then the changes are made, otherwise no parameters
are affected. A proposed set of parameters can result from user interaction with the printer user
interface or HP-PJL host utilities.
For example, the Serial Port Group is a group of parameters within the Communications Parameters
Class. There is a consistency function associated with this collection of parameters that will ensure that
the set of variables is a legal and consistent set.

5.1.3 Parameter Environments

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