HP 2500 HP PCL/PJL reference - Printer Job Language Technical Reference Manual - Page 113

Status Readback Commands, Introduction

Page 113 highlights

7 Status Readback Commands Introduction PJL allows applications to request configuration and status information from the printer. The printer also can be programmed to send unsolicited status information to the application when printer events occur. For example, the printer can send status information indicating the printer door is open, toner is low, online/offline status, the text displayed on the control panel, and other pertinent information. PJL status readback is especially useful during application development. Status readback enables you to determine that your application successfully changed feature settings to your specifications. This chapter describes the requirements for using status readback, and explains the following status readback commands: • INQUIRE requests the current value (PJL Current Environment) for a specified environment variable. • DINQUIRE requests the default value (User Default Environment) for a specified environment variable. • ECHO returns a comment to the host computer to synchronize status information. • INFO requests a specified category of printer information. • USTATUS allows the printer to send unsolicited status messages, including device, job, page, and timed status. • USTATUSOFF turns off all unsolicited status. This chapter also explains job recovery. EN Status Readback Commands 7-1

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EN
Status Readback Commands 7-1
7
Status Readback
Commands
Introduction
PJL allows applications to request configuration and status
information from the printer. The printer also can be programmed to
send unsolicited status information to the application when printer
events occur. For example, the printer can send status information
indicating the printer door is open, toner is low, online/offline status,
the text displayed on the control panel, and other pertinent
information.
PJL status readback is especially useful during application
development. Status readback enables you to determine that your
application successfully changed feature settings to your
specifications.
This chapter describes the requirements for using status readback,
and explains the following status readback commands:
INQUIRE requests the
current
value (PJL Current
Environment) for a specified environment variable.
DINQUIRE requests the
default
value (User Default
Environment) for a specified environment variable.
ECHO returns a comment to the host computer to synchronize
status information.
INFO requests a specified category of printer information.
USTATUS allows the printer to send unsolicited status
messages, including device, job, page, and timed status.
USTATUSOFF turns off all unsolicited status.
This chapter also explains job recovery.