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CAN Bus rate Problem?

Marcel 9 months ago in IQANdesign updated by Gustav Widén (System support) 8 months ago 1

In my project I can adjust the CAN Bus speed of CAN2 depending on a variable. I set this speed in the initialisation of the devices. We use a MC41 and a MD4-7. I made this a couple of years ago and worked since then without problems., But now we have a CAN Bus error which comes after startup since a few weeks. Because we cannot find any reason why this suddenly happens and we read this article:

https://forum.iqan.se/en/knowledge-bases/2/articles/621-no-contact-and-critical-can-bus-error

I begin to wonder if this could have affect on the problem. Is there something changed in the Parker firmware and maybe the CAN bus Speed is set to slow in one of the devices?

Image 3067

I do not think the warning symbol seen on the property is the issue. That is from a recent change in IQANdesign that helps highlight project check warnings. If you select the Speed property that has the warning, I am guessing you will just see "Unit mismatch" warning. 

The bitrate is controlled by initialization channel and is only set on startup. 

So an error in how the bitrate is calculated would be immediate. 

If you have the wrong bitrate on the bus, the CAN bus error would come very quickly after attempting to send a few messages.