Hello Mark and thank you for the post.
The CAN Protocol decode feature of PicoScope software should also apply to SWC
We need to consider the voltage states present on this single wire to ensure we select the relevant protocol.
I am not familiar with the voltage thresholds responsible for a recessive or dominant outcome. Would you know if the voltage switches from low to high or high to low?
Could you post a psdata file of your capture we can check the results?
If the voltage switches from low to high then I would select the CAN HI protocol in the serial decoding settings box, followed by Auto Set-up, where PicoScope will take of Baud rates and voltage thresholds.
Regarding the data obtained once decoded, could you take a look here at topic11261.html
This is an interesting topic that we can all benefit from once we convert to meaningful data.
I hope this helps and any feedback you can provide would be most helpful.