HP Color LaserJet 5500 Technical Reference Manual page 194

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.)
10-14 Programming Tips