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

EN Status Readback Commands 7-33
Comments:
Unsolicited status allows you to automatically receive device, job,
page, or timed status without requesting it. Each type of unsolicited
status provides different information and is described on the following
pages.
Some printer models may have more (or fewer) types of unsolicited
status than DEVICE, JOB, PAGE, and TIMED. You can have the
printer list the various types of unsolicited status by issuing the INFO
USTATUS command. See “Example: Using the INFO USTATUS
Command” for an example of this.
Unsolicited status, except for TIMED, can be turned off individually
using the OFF parameter, such as in the USTATUS JOB=OFF
command. TIMED status is turned off by setting it to zero.
Alternatively, all unsolicited device status can be turned off using the
USTATUSOFF command.
DEVICE Variable
The USTATUS DEVICE = value command prompts the printer to send
status messages when device changes occur. When DEVICE = ON,
the printer sends status information for all changes to printer status.
When DEVICE = VERBOSE, the printer also sends status
information for all PJL parser warnings and errors.
Part of the unsolicited status message sent to the host is a 5-digit
code that indicates the status condition. The first 2 digits divide the
status codes into different categories. The general status categories
are listed in the following table. (This is only a general summary of the
specified categories. The full status code listing is located in
Appendix D.)
If there is a “DISPLAY=string” portion of the status message, the
string is localized; the same message as that displayed on the control
panel appears in whichever language is being used.