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

7-6 Status Readback Commands EN
Note The permissible variables and range of values for each variable may
not be the same in all HP LaserJet printer models. See Appendix A
for a list of valid variables, or send the @PJL INFO VARIABLES
command to request this information directly from the printer.
value This parameter is the returned value of the requested
variable. For example, if you send the @PJL INQUIRE
COPIES command, and the PJL Current Environment setting
is 65, the returned value is 65, indicating 65 copies. See
Appendix A for variable names for each parameter.
Parameters:
Comments:
If your application has status readback capabilities, you can request
the current setting of any valid environment variable. Since the
INQUIRE command returns only the value for one feature, you can
send multiple INQUIRE commands to request information about more
than one feature. If you need information about many variables, the
PJL INFO VARIABLES command returns the PJL Current
Environment settings for all environment variables.
If the printer does not support the variable, the response is:
@PJL INQUIRE [LPARM:personality | IPARM:port]
~variable <CR><LF>
"?"<CR><LF>
<FF>
Parameter Variable Names+
personality PCL ESCP
POSTSCRIPT (other personalities may
be supported)
port PARALLEL Supported on HP
LaserJet 4PJ only
SERIAL
variable Valid variables for each printer are listed in
Appendix A.
value Acceptable values for each variable are also
listed in Appendix A.