HP Color LaserJet 5500 Technical Reference Manual page 58

Example: Using PJL
This example demonstrates how to set a password and to
lock the control panel so users cannot modify control panel
Security
settings. It is assumed the password value at the start of
job is 7654. The example changes the password to 1776.
<ESC>%-12345X@PJL <CR><LF>
@PJL COMMENT **Set Password** <CR><LF>
@PJL COMMENT **& Lock Control Panel**<CR><LF>
@PJL JOB PASSWORD = 7654 <CR><LF>
@PJL DEFAULT PASSWORD = 1776 <CR><LF>
@PJL DINQUIRE PASSWORD <CR><LF>
@PJL DEFAULT CPLOCK = ON <CR><LF>
@PJL DINQUIRE CPLOCK <CR><LF>
@PJL EOJ <CR><LF>
<ESC>%-12345X
To unlock the control panel, you would send a job similar to
the following job. This job specifies the correct password
with the JOB command, and then uses the DEFAULT
command to unlock the control panel.
<ESC>%-12345X@PJL <CR><LF>
@PJL COMMENT **Unlock Control Panel** <CR><LF>
@PJL JOB PASSWORD = 1776 <CR><LF>
@PJL DEFAULT CPLOCK = OFF <CR><LF>
@PJL DINQUIRE CPLOCK <CR><LF>
@PJL EOJ <CR><LF>
<ESC>%-12345X
5-12 Job Separation Commands