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

EN Using PJL 3-3

PJL Job Requirements

PJL has certain job requirements that must be met to work correctly.

Jobs that satisfy the following requirements are “well-formed” and

work well with all PJL printers, both in single-computer/single-printer

environments and network environments. Here are the requirements:

• All PJL jobs must begin and end with a UEL command

(<ESC>%–12345X). This command exits the current printer

language and returns control to PJL.

• The UEL command at the beginning of the job must be

immediately followed by the PJL command prefix (@PJL). The

“@PJL” can be followed by an optional carriage return and a

required line feed character, or it can be the prefix of another

PJL command (see the two following examples). No other

characters, including control characters, are allowed between

the UEL command and the @PJL prefix.

• The UEL command at the job end must not be followed by

anything (except the first character of the next job).

• Line Termination—a line feed character (<LF>) is required to

terminate all PJL commands (except the UEL command). A

carriage return can precede the terminating line feed, however

the carriage return is optional and is ignored.

• No blank command lines are allowed. The command

@PJL [<CR>]<LF> is provided for situations where a blank

line is needed to add space between command lines.

The following command lines demonstrate two ways to begin a job

while satisfying PJL requirements. Both lines begin with a UEL

command, are immediately followed by @PJL, and are terminated

with a line feed character. All PJL jobs also must end with a UEL

command. The examples on the following page demonstrate how to

begin and end a PJL job.

<ESC>%–12345X@PJL COMMENT *Start Job* <CR><LF>