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stlehmann / pyads

Python wrapper for TwinCAT ADS
MIT License
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add_route_to_plc fails under Linux #432

Open vrees opened 6 days ago

vrees commented 6 days ago

I want to connect to my Beckhoff PLC, CX5110, running TwinCAT 3.1, build 4024.62 via ADS protocol under Linux. While trying to add_route_to_plc an error occurred in the pyads lib:

main_py

ErrorMessage: ` Connected to pydev debugger (build 242.23339.11) Traceback (most recent call last):

File "/home/vrees/.local/share/JetBrains/IntelliJIdea2024.2/python-ce/helpers/pydev/pydevd.py", line 1570, in _exec pydev_imports.execfile(file, globals, locals) # execute the script ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/vrees/.local/share/JetBrains/IntelliJIdea2024.2/python-ce/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile exec(compile(contents+"\n", file, 'exec'), glob, loc)

File "/home/vrees/work/git-repos/heatpump2influxdb/main.py", line 15, in pyads.add_route_to_plc(CLIENT_NETID, CLIENT_IP, PLC_IP, PLC_USERNAME, PLC_PASSWORD,route_name=ROUTE_NAME)

File "/home/vrees/work/git-repos/heatpump2influxdb/venv/lib/python3.11/site-packages/pyads/ads.py", line 200, in add_route_to_plc return adsAddRouteToPLC( ^^^^^^^^^^^^^^^^^ File "/home/vrees/work/git-repos/heatpump2influxdb/venv/lib/python3.11/site-packages/pyads/pyads_ex.py", line 169, in wrapper return fn(*args, **kwargs) ^^^^^^^^^^^^^^^^^^^ File "/home/vrees/work/git-repos/heatpump2influxdb/venv/lib/python3.11/site-packages/pyads/pyads_ex.py", line 375, in adsAddRouteToPLC raise RuntimeError(f"Unexpected response from PLC: {data!r}")

RuntimeError: Unexpected response from PLC: b"\x03f\x14q\x00\x00\x00\x00\x06\x00\x00\x80\x05|\xca\xe0\x01\x01\x10'\x01\x00\x00\x00\x01\x00\x04\x00\x04\x07\x00\x00" python-BaseException `

The debug output shows, that the PLC answers with reasonable data. But the check if the received password is correct, fails as the expected data does not match the true or false condition. It looks like that the parsed data is somehow wrong interpreted. I double checked username and password as it is still the default password.

debug

chrisbeardy commented 5 days ago

hmmmm not seen this error before! It looks like the plc is sending a repsonse that we are not expecting, because the password should either be correct or not. I wonder if Beckhoff have changed the expected response, I've not tested myself with 4024.62, thats quite a new one. You don't have the ability to try another runtime?

vrees commented 5 days ago

The CX5110 uses a Windows CE7 Operating System. Changing the Runtime is quite complex as it uses SD cards for the installation. And I was happy to get it running so far. I would be very reluctant to change that. Any other ideas?

chrisbeardy commented 5 days ago

ah, this is not the first time we have had issues with CE7 (#188 and #232 and #257) , I suspect there may be some overlap here. Maybe caused by something related to sizes on the platform (e.g. https://stackoverflow.com/questions/384502/what-is-the-bit-size-of-long-on-64-bit-windows#384672). This may be an internal problem we need to address to make sure we can read password on all platforms. I don't have a CE platform to test with, so this may take some time to resolve. Please feel free to look into this problem yourself to see if you can find a solution and we can merge it in.