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

EN Programming Tips for Using PJL 11-15
When USTATUS PAGE = ON, the first unsolicited page status
message is sent after page 1 lands in the output tray:
@PJL USTATUS PAGE
1
<FF>
Additional page status messages are sent after each succeeding
page lands in the output tray. After the job is completely printed, the
host receives unsolicited page and job status as follows (assuming a
38-page job):
@PJL USTATUS PAGE
38
<FF>
@PJL USTATUS JOB
END
NAME="End of Monitor Job"
PAGES=38
<FF>
The unsolicited page status indicates that the 38th page printed. The
job status indicates that the EOJ command was received, and that 38
pages were printed. (The page count is incremented by one for each
simplex page formatted, and by two for each duplex page formatted.)