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

7-36 Status Readback Commands EN
JOB Variable
The USTATUS JOB = ON command is used to notify the application
every time a JOB command is encountered, when the final page of a
job is in the output tray and an EOJ command has been received, and
when a job has been canceled (only for those printers that support job
cancellation such as the HP LaserJet 4000 series and 5000 series
printers). This is useful for spooling applications requiring feedback
indicating that a particular job has started or completely printed.
If job status is enabled and the printer receives a JOB command, it
resets the page count associated with the unsolicited page status and
returns a job status message.
Note Resetting the page count associated with unsolicited page status
affects only future pages. Pages that are already processed, but not
yet printed, are not affected.
The PAGES=number of pages information associated with unsolicited
EOJ status indicates the number of pages printed on paper. It does
not include any page images that were processed in non-printing
mode (see the “PAGE Variable” discussion.) When in the duplex
mode, each side of a duplex page counts as one page.