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

EN Status Readback Commands 7-15

Use the ECHO command to synchronize status so that you know the

status you are receiving is the requested status. To do this, send an

ECHO command to the printer, and then discard the incoming status

messages until your message is echoed back. Eliminate all data

received from the printer up to the echoed response string. For the

remainder of your print job, you can be sure that all status messages

you receive after your echoed message were requested by your

application. If you turned on USTATUS, you may receive unsolicited

status information at any time.

Example: Using the ECHO Command

This example sends the Testing 68394 10:57:06.4 message

using the ECHO command. After the application receives the

Testing 68394 response, all succeeding solicited messages

received during the current job are those requested by the current

application.

@PJL COMMENT Using the ECHO command <CR><LF>

@PJL ECHO Testing 68394 10:57:06.4 <CR><LF>

<ESC>%-12345X

A sample HP LaserJet 4 printer response for this example is shown

below. Other PJL printers may have different responses.

Related Commands:

INQUIRE, DINQUIRE, INFO, SET, DEFAULT, USTATUS

@PJL ECHO Testing 68394 10:57:06.4<CR><LF>

<FF>