1. GK420T Desktop Thermal Printer User Guide
  2. Diagnostics and Troubleshooting
  3. Communications Diagnostics
  • GK420t Desktop Thermal Printer User Guide
Communications Diagnostics

Communications Diagnostics

If there is a problem transferring data between the computer and printer, try putting the printer in the communications diagnostics mode.
The printer will print the ASCII characters and their respective hexadecimal values for any data received from the host computer.
You can enter hex data dump mode using one of the following methods:
  • Use the ZPL programming
    ~JD
     command
  • Use the EPL Programming
    dump
     command
  • Turn printer power ON while holding down
    FEED
    . For details, see Power-Off FEED Button Modes.
The printer prints
Now in DUMP
 and advances to the top of the next label.
Here is a sample communications
DUMP
 mode printout. It displays hexadecimal data
00h-FFh
 (
0-255
 decimal) with a unique character for each hexadecimal value displayed above the hexadecimal data.
Serial port and Bluetooth data-handling errors are 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 ON. Alternatively, press
FEED
 as many times as necessary to clear the printer’s command buffer and print
Out of DUMP
 on the label. The printer prints
Out of DUMP
.