Diagnosing Communication Issues
Diagnosing Communication Issues

Diagnosing Communication Issues

If there is a problem transferring data between the computer and the printer, try placing the printer in Communications Diagnostics mode. The printer will print the ASCII characters and their respective hexadecimal values for any data received from the host computer:
  1. To enter diagnostic mode, do one of the following:
    • Send the ZPL
      command- to the printer. (See the ZPL Programming Guide.)
    • Send the EPL 
      command to the printer. (See the EPL Programming Guide.)
    • Use the
      button after turning printer power ON. (For details, see FEED Button Modes – Power OFF.)
    The printer prints the following:
  2. Retrieve the printout and and use the information below to understand the report.
The Communications Diagnostic printout displays hexadecimal data (
which is 0-255 decimal) with a specific character for each hexadecimal value displayed above the hexadecimal data.
Serial port and Bluetooth data handling errors (listed here) get logged in the blank lines between the lines of data:
  • F
    = Frame error
  • P
    = Parity error
  • N
    = Noise error
  • O
    = Data overrun error
To exit diagnostic mode and resume printing, turn printer power OFF and then back ON. Alternately, press the
button as many times as it takes to clear the printer’s command buffer and print 
Out of Diagnostic mode
on the label.