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Router not responding to messages with BRS bit set to 1

Posted: Thu 3. Mar 2022, 22:52
by rotundron
Hi,

The FD router is responding correctly to messages with BRS flag set to 0 (I believe this uses data rate = baud rate) and fails when BRS is set to 1. The reported error seen in CANoe which is sending the message is: Not acknowledge error, dominant error flag, BitPosition = 561. The data rate is set to 2mbps while the baud rate is 500kbits.

My current guess is that the router is attempting to receive the data portion of the message at the wrong speed and causing this error. If this explanation makes sense how do I update the data rate on the router?

Thanks,
Cameron

Re: Router not responding to messages with BRS bit set to 1

Posted: Fri 4. Mar 2022, 11:22
by PEAK-Support
When the BRS is set to 1 - you need to be sure that the Data Bitrate Setting fit to 100% to the rest of your CAN Nodes.
Check on your CANoe how exact the 2MBit settings are and use the timing (tseq1/2 , SP etc.) in your own code on the Router FD. (see can_user.h )

Re: Router not responding to messages with BRS bit set to 1

Posted: Fri 4. Mar 2022, 16:49
by rotundron
Thanks for the quick reply.

My CANoe settings are as so in the:
Capture.PNG
Capture.PNG (45.33 KiB) Viewed 5180 times
As for the second point, I'm now looking into the can_user.h code but my knowledge base isn't enough that I understand the timing structure or what was meant by SP.
Is there a document or example project available that I can use to learn this from?

Re: Router not responding to messages with BRS bit set to 1

Posted: Fri 4. Mar 2022, 17:04
by O.Hartkopp
Hi!

As Mr. Wilhelm stated "Check on your CANoe how exact the 2MBit settings are and use the timing (tseq1/2 , SP etc.)"

You need to open the dialog with the "+" buttons to see the detailed bitrate settings that have to match in all CAN nodes.

Re: Router not responding to messages with BRS bit set to 1

Posted: Fri 4. Mar 2022, 17:37
by rotundron
Ah, I had misunderstood what was meant.

This makes much more sense.

Thank you.