My label print situation and some questions

[icvdok]

Label Printing Setup

I would like to share my situation regarding my label printing setup and the gaps I am experiencing to understand if there are issues or if my setup needs adjustments.

I have two Brother label printers: QL-820NWB and PTZ. The QL supports 65mm labels, which I use mainly for printing location labels to apply on boxes, shelves, and other types of locations. The PT-P750W supports up to 24mm labels, but I am using classic 12mm labels for Gridfinity bins.

I have installed the Brother plugin, and it appears to be installed and active, but it is not listed when I attempt to print something. I have configured the QL as a machine, and it works, but the server reports an error with each print (although the label is printed). I tried to add the PT as a second machine, but there is no way to add the network configuration.

I also attempted to create a custom label printer to print 12mm labels, but without a working printer configuration, I don't want to invest too much time.

Is what I am trying to achieve too challenging with the current InvenTree capabilities, or do I have issues with my setup? For example, why is the Brother printer not listed anymore (it was in the previous version)? Can the Brother driver support two printers? Is there a compatibility list of the Brother-supported printers?

Many thanks for any feedbacks

[SchrodingersGat]

@icvdok does your issue match the description here - #9327 ?

[icvdok]

Similar but not the same. I've probably multiple issues but let's focus on the primary. I can see the printer withint the machine list

then this :

and finally the server error:

Error object (29)
History

Type:
PicklingError
Path:
InvenTree.offload_task
Info:
Can't pickle <class 'inventree_brother.brother_plugin.BrotherLabelPrinterDriver'>: it's not the same object as inventree_brother.brother_plugin.BrotherLabelPrinterDriver
When:
March 18, 2025, 2:11 p.m.
Data:
Traceback (most recent call last):

File "/home/inventree/src/backend/InvenTree/InvenTree/tasks.py", line 208, in offload_task
task.run()

File "/root/.local/lib/python3.11/site-packages/django_q/tasks.py", line 730, in run
self.id = async_task(self.func, *self.args, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/tasks.py", line 71, in async_task
pack = SignedPackage.dumps(task)
^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/signing.py", line 16, in dumps
return signing.dumps(
^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django/core/signing.py", line 152, in dumps
return TimestampSigner(key=key, salt=salt).sign_object(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django/core/signing.py", line 250, in sign_object
data = serializer().dumps(obj)
^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/signing.py", line 36, in dumps
return pickle.dumps(obj, protocol=pickle.HIGHEST_PROTOCOL)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

_pickle.PicklingError: Can't pickle <class 'inventree_brother.brother_plugin.BrotherLabelPrinterDriver'>: it's not the same object as inventree_brother.brother_plugin.BrotherLabelPrinterDriver

Here some printer settings:

[SchrodingersGat]

@icvdok regarding the pickling error - this has been addressed in #9171

Please update to the latest stable version and verify that the issue is no longer present

[icvdok]

Hello Oliver, some update:
I'm now on the last version 1.17.9 and it'seams that both printers are stable initialized:

The "default" selection for the printers is:

and this is what's in the list:

The same error is reported:

but the label has been printed successfully.
Let me know if you need other info or tests and thanks for the support.

[wolflu05]

Not sure, you need to select InvenTreeLabelMachine now and then in the now appearing select your specific printer. Then the label should print, and you should see two messages at the bottom, one saying something like the label printing was started succesfully and one saying that an error occured, the label could not be printed (ref: #8511).