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CANopenNode / CanOpenSTM32

CANopenNode on STM32 microcontrollers.
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SDO download fails with message flood #51

Closed dakhnod closed 5 months ago

dakhnod commented 8 months ago

Using candump, I often times observe the following behaviour on the CAN bus when my PI (using python-canopen) tries to upload an SDO to Node-id 3 (stm32).

can0  603   [8]  21 00 70 01 40 00 00 00
can0  583   [8]  60 00 70 01 00 00 00 00
can0  603   [8]  00 00 80 00 C0 C0 00 00
can0  583   [8]  20 00 00 00 00 C0 00 00
can0  583   [8]  00 00 00 00 00 20 00 00
can0  583   [8]  00 20 00 00 00 00 00 00
can0  583   [8]  00 00 00 00 00 00 00 20
can0  583   [8]  00 00 00 00 00 20 00 00
can0  583   [8]  00 00 00 00 20 00 00 00
can0  583   [8]  00 00 00 20 00 00 00 00
can0  603   [8]  10 00 00 00 00 00 00 00
can0  583   [8]  30 00 00 00 00 00 00 00
can0  583   [8]  30 00 00 00 30 00 00 00
can0  583   [8]  00 00 00 00 30 00 00 30
can0  583   [8]  00 00 30 00 00 00 00 30
can0  583   [8]  00 00 30 00 00 30 00 00
can0  583   [8]  00 00 30 00 00 00 00 00
can0  583   [8]  00 00 30 00 00 00 30 00
can0  583   [8]  00 00 30 00 00 00 30 00
can0  583   [8]  00 00 30 00 00 30 00 00
can0  583   [8]  00 00 30 00 00 00 00 00
can0  083   [8]  00 00 00 01 00 00 00 00
can0  703   [1]  05
can0  603   [8]  80 00 00 00 00 00 04 05
can0  603   [8]  0F 00 00 00 00 00 00 00
can0  603   [8]  0F 00 00 00 00 00 00 00
can0  583   [8]  80 00 70 01 01 00 04 05

The way I see it, the node is putting out garbage on the bus starting from line 5. This then disrupts the canopen stack on the PI and the SDO download fails.

Is there any obvious error in my thinking? Is this a common error that is easily fixed? Do those multiple messages from the node have any purpose, or are they really just a glitch?

Any help will be apreciated.

HamedJafarzadeh commented 5 months ago

I've never seen such a thing before. I think it is either hardware fault (Termination problem) or misconfigured node communication parameters IMO.

dakhnod commented 5 months ago

Hopefully this helps someone in some distant universe:

My STMs were configured to use the internal Clock instead of an external one. The drift between them seems to knock out the can bus. Fixed now. Thanks.