The module described in this article has been marked as a legacy module. This means the following:
We don't create new features for this module or fix any bugs.
The module is not available anymore in Xentral instances (demo or licensed) created after 28-Sep-2022. If you as a new user have special requirements that could only be fulfilled by this module, please contact our customer support team to discuss a solution.
For more information, see also Why is Xentral deprecating some modules (Legacy modules) and what does this mean for you?
You can connect your label printer to Xentral in the same way as your regular printer via the printer spooler, as described in this article: Connecting your printer to Xentral. The adapter box is not required!
This step-by-step guide shows how to set up a label printer that is connected to xentral via an adapter box. The following items are required for the setup:
Label printer Zebra GK420t, incl. power supply (link to store)
Raspberry PI (in the following called adapter box) conifigured according to instructions
USB cable to connect the printer to the adapter box
Network cable (or WLAN USB stick in case of wireless network connection) to connect the adapter box to the network
USB stick (empty, FAT formatted)
Thermal foil, suitable for Zebra GK420t
Label printers can also be connected to the xentral spooler, in which case it is preferable to use a network-compatible label printer.
Unpack the label printer and make sure that all parts are present and undamaged. The adapter box is not yet necessary for carrying out the first 5 steps of these instructions.
Open the cover of the label printer by pressing the green latches on the side in the direction of the front of the device
Unpack the thermal foil and peel off the supplied cardboard roll by hand
The beginning of the thermal foil is to be detached from the roll and wound onto the cardboard roll - two to three windings are sufficient. The cardboard roll serves as a carrier for winding up the used thermal foil during printing (hereinafter also referred to as empty roll)
The two rolls in the cover of the label printer are to be inserted into the holders provided. Note that the full roll is inserted from the bottom and the empty roll from the top (see photos). To insert, press the cardboard rolls against the spring-loaded conical hubs and snap them into the opposite hub
When both rolls are inserted, check that they are seated correctly by unscrewing one or two windings using the green wheel next to the empty roll
Take the label roll and insert it into the lower part of the label printer as shown in the illustration. The roll is held between the two green hubs by spring pressure. The beginning of the roll is to be inserted as shown to the output slot of the device. Then close the cover of the printer.
The label printer must be calibrated to the label size. Calibration must be performed each time after loading a label roll! To perform the calibration, follow these steps:
If necessary, close the cover of the printer
Connect the power supply to the device and press the power switch on the back of the device on the bottom left side
Press and hold the key on the top of the label printer housing until the LED next to the key flashes 2 times in a row (4 flashes → printer is reset to factory settings.). Then release the key - the printer will now calibrate itself to the size of the loaded labels
When holding the button, the LED first flashes once, after a short pause twice, then three times and so on...
The print intensity should be configured so that the labels are easily readable, especially for barcode scanners. The key on the top of the label printer housing should be pressed and held until the LED next to the key flashes 6 times in succession. Then immediately release the button. The device will then begin to print several test printouts, gradually increasing the print intensity. As soon as the printout is clean and legible, briefly press the key on the top of the housing once to confirm the setting.
To connect xentral with the external device (label printer, scale, receipt printer, cash register displays etc.), it needs a small "intermediate server" (adapter box), which you can buy. Solutions for this can be found at our partner Ruhr Agency.
For technical reasons, a Raspberry Pi up to max. version 3B is currently required.
Once the adapter box is purchased, it can be configured with the following steps:
Connect the adapter box to a monitor and keyboard and mouse. Also, make sure that there is an Internet connection.
Install the operating system and confirm the following message with OK
Go to LX Terminal (taskbar dark icon) and enter the following commands. Then confirm each of them with the ENTER key
sudo apt-get --yes install libcurl3 php7.0-curl php7.0-cli php7.0-xml
sudo usermod -a -G lpadmin pi
sudo systemctl enable ssh
sudo dpkg -i adapterbox.deb
echo "Seriennummer eingeben gefolgt von einem [ENTER]:"
echo "<?php \$config['serial'] = '$seriennummer'; ?>" > /tmp/config.php
sudo mv /tmp/config.php /root/config.php
The echo commands, with the exception of the last call, are for illustrative purposes only.
You can downlaod the Debian file (deb file) for the wget command in the GitHub-Download directory.
If the execution of the script does not work, you may need to install and activate the PHP version with the corresponding extensions.
sudo apt -y install php php-common
sudo apt -y install php-cli php-fpm php-json php-mysql php-zip php-gd php-mbstring php-curl php-xml php-pear php-bcmath
Wait until you are prompted to enter a serial number. Enter a 9-digit number and confirm it with the ENTER key - this serial number will be used later in xentral. The box will switch off automatically. After that the adapter box is configured and you can continue with the next step.
If your printer does not print, change the driver from cpcl to zpl (Zebra zb 230). You can find more information on these pages:
To continue setting up the label printer, go to a computer workstation with the adapter box and log in to xentral with an account with sufficient rights. In the view Administration → Settings → System open the 'Basic settings'.
Open the tab 'API's' and select the marked option. Then click on "Generate Key" and save.
In the Administration → Settings → System view, open the 'Adapter box' item.
In the adapter box view, select 'NEW'. After that, xentral will guide you through the setup in 3 steps.
First, if necessary, the network settings can be defined manually. If changes are made here, these must be saved. To proceed to the next step, click on 'Continue with step 2'.
xentral recommends using a network cable as this is the best and most stable way. Operation via WLAN is possible in principle, but is not supported by xentral, since this is rather error-prone and the possible problems are mainly to be found in the network settings.
For this step, xentral provides a list of actions to be performed. This list has to be worked through carefully in the given order. Then the FAT formatted USB stick is needed.
Once you have worked through the list, take the label output by the printer back to your computer workstation and click 'continue with step 3' in xentral.
Now assign a name to the label printer you just set up and enter the serial number your printer printed on the label in the previous step (third line on the label in the figure above).
In the Administration → Settings → System view, open the 'Printer' item.
The configured label printer appears in the list. Click on the Edit icon to make settings for the printer.
Set 'Label printer' as the device type. For Format, set the size of the labels loaded in the printer. The connection type must still be set to 'Adapter box'.
Now make sure that the USB connection between printer and adapter box as well as the network connection of the adapter box is established. The devices are to be supplied with voltage and the printer is to be switched on in order to test the printer in the following.
Now a test print has to be performed to check if the integration of the printer has worked correctly. To do this, open the Warehousing & Logistics → Label Printer view in xentral. Enter any short text in the top text field and click on 'Print'. If the entered text is printed by the label printer, the setup was successful.
Until version 21.1 it's via Management → Label Printer.
The creation of label layouts is described here.
Labels can be printed individually directly as PDF. The labels are retrieved via the spooler (directly in the printer settings) Or the PDF can be sent to an e-mail address. The type of connection can be selected directly.
Connection via command line command/PDF in directory:
Directory → specify the directory (e.g. /tmp/ can be used for Linux).
When connecting to an e-mail address, fill in the following fields:
Email Printer Recipient → Email address to which the PDF will be sent.
Email Printer Subject → Subject that this above email will receive.
E-Mail Printer Text → Additional text that will be sent in the above mentioned e-mail: entwickler:etikettendrucker_email.png
The labels can also be created as XML. The only difference to the printer is that the label sizes are not fixed and can be set arbitrarily. Setting of the arbitrary size directly in the label generator.
A label printer can also be used for shipping labels. This must be selected in the logistics process for the parcel label labels. The following settings must be made in the printer itself (connection via command line command):
Device type → Printer (label printer is used only in conjunction with the xentral labels)
Format → DinA5
Connection → Command line command
Command or directory → lpr -o fit-to-page -o media=A6 -H 192.168.0.XXX -P ZebraGC420d
Serial number → Please enter your serial number here (for the spooler correspondingly the serial number for the branch)
lpr -o fit-to-page -o media=A6 -H 192.168.0.XXX -P ZebraGC420d
The bold areas (see above) must be replaced by your own designations.
To set up a custom label label format, first go to the label printer settings under xentral. This can be found under → Administration → Settings → Printer → "Select your label printer". The format must be changed to "blank".
In the next step, the CUPS server must be launched on the Linux print server. For this purpose, the following address must be entered in the web browser:127.0.0.1:631