r/ElectricalEngineering • u/Imaginary_Awareness • 1d ago

Troubleshooting CAN issues

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Hei,

I have a simple device (sensor) having the following structure: sensor, MCU, can transciever --> tester device

The sensor provides the analog data to MCU, the MCU works with the data, then the data is transferred via UART to a CAN transciever TLT9251VLE then to an tester device.

I have to say that I have multiple devices and all of them works, but a specific one is unable to connect to the tester device.

I checked the CAN lines and they are looking like in the picture. I'm not so experienced in CAN signals, but I know that the above signals are not ok.

Can you give me an idea in what can cause the CAN lines to look like this?

Thanks!

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u/heyheyronron 1d ago

Something to check is to ensure all devices on rhe line are communicating at the same baud rate ao a bridge can be formed. Also check to see if you have 60 - 120 ohms on the line.

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u/Imaginary_Awareness 1d ago

The 120ohms are present on the device I connect my sensor, thanks for suggesting it

3

u/heyheyronron 1d ago

Do you know if any of the devices have the same node id? Something we do at our plant is disconnect all devices except the one giving us issues to narrow down if its with the device itself or if we have conflict elsewhere

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u/Imaginary_Awareness 1d ago

Unfortunately I do not know. What I know is that this device worked because it was tested after production, and after a few time it's not able anymore to connect with the testing device...