21.18. Label printer installation

We recommend Zebra GK420 TT printers with a network port. You may use other printers that support the ZPL printing language (or EPL if using mSupply 3.2 or earlier), but we can not provide much support for these models as we have not used them ourselves.

  1. Load the printer with ribbon and labels.
  2. Turn on
  3. Plug in network cable.
  4. By default the printer is set to obtain an address by DHCP. Assuming you have a DHCP server on your network: press the button on the front and hold until it flashes once, then release the button. A configuration label will print. Note the IP address. If the printout is the wrong width and unreadable, see “Setting label width” below
    1. You may also be able to get the IP address from the list of DHCP leases when logged in to your router (e.g. for pFsense: Status > DHCP )
  5. There are now 2 options for setting a static address
    1. (Preferred method): Configure your DHCP server to assign a static address to the printer. Note that after doing this, you may have to turn the printer off and back on to get the new address from the DHCP server.
    2. Alternative: Assign a static address on the printer itself. The default static address for the printer is
      1. You can now log on to the printer using it's current IP address http://printer_ip_address where printer_ip_address is the current printer's ip address.
      2. Go to “Print Server Settings”, then click “Print Server” and log in
        • user: admin
        • pass: 1234
      3. Go to “TCP/IP Configuration” and set an IP address that is not within a range controlled by DHCP (Ping it to ensure it is not already assigned)
      4. Set the IP Protocol to “Permanent”, and submit
      5. Reset the printer (you can do this from the web interface)
  6. Ping the IP address you have set to ensure the printer has the right address
  7. Finally, tell mSupply about the printer: see Printing Preferences for instructions on doing that.

Note that you do not have to do this to get the right width when printing from mSupply. This is only for viewing a configuration label before using mSupply:

Hold down the button on the front of the printer - it will flash once, then twice, then three times, then four times, then five times: immediately release the button. Labels will print with a box that gets wider with each one: press the button again when the box is the width of the label. If needed, you can use the “one flash” sequence above to print out the IP address and other information once you have the printer detecting the label width correctly.

The following flash sequences occur in order by holding down the front button (“3” means you hold the button and it flashes once, then twice, then three times, and you immediately release the button for that action to be performed)

  1. Print status
  2. Media callibration: use to make the printer detect the length of the labels you're using
  3. Serial port config: not needed
  4. Factory defaults: Sets everything back to default settings
  5. Print width adjustment (above)
  6. Print Darkness (Density) Adjustment
  7. Manual media calibration (you most likely don't need this)

For various reasons the printer may need to be re-calibrated. The act of “calibrating” is essentially to allow the printer to work out the size of label that is being used.

There are many levels of Calibration but we will try the basic one.

  • Switch on the printer.
  • Press and continue pressing the button button until the light :
    • flashes once
    • flashes twice »> then let go of the button.
  • The printer will print and waste a few label.
  • click the button once.
  • Calibration is theoretically complete
  • Then see if label printing works.

Over time, the printer will fail to perform due to collection of dust. We imagine sweat particles will cause friction on the moving parts of the printer and this hinders performance. So in many cases throughly cleaning the printer ends up reviving a printer that seems broken. Please follow the steps below to clean :

  • Take the printer off the mains….. So un-plug the electric.
  • Take out the ribbon and label, cleaning the printer with small amount of Isopropyl swipes.
    • Wipe the print head.
    • Wipe the paper roll holder.
    • Wipe the track that the paper travels on.
    • The last black roller : Turn the roll and wipe.
    • Lastly clean the outside of the printer and appearance :-)
  • Leave for 20 minutes
  • re-connect the ribbon and label.
  • re-connect the printer to the mains.
  • Go through the calibration mode.
  • See if the printer behaves.

  • Last modified: 2019/10/28 20:41
  • by Emily Porrello