I did measure bus load with PCAN Diag2 and found that average is around 14%, max is between 70 and 100 %.
How should I interpert this? If I refer to the average I would say the bus load is ok...
I used 200ms as sample interval, is this correct?
I'm measuring a bus working at 250 kbit/s.
Thanks.
How to interpret Busload?
How to interpret Busload?
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- Bus load graph
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Re: Bus Load
Hello,
the max. busload of 70%..100% means that there is a message burst within the selected time intervall of 200ms.
You cannot select a "wrong" measure window, it depends on what yo want to see.
You can modify the measure window from very small to very large and look for the average and max. value. If the messages are equally distributed, then the average and max. value stay very similar. If you reduce the measure window to the minimum value you might see 100% max. busload for a short periode followed by a value smaller than the average for a longer periode. This means there is a message burst. If the average bus load is not too high this does not indicate a problem, it just helps you to get more information about the message distribution over time.
Please also look for the error rate. The peak bus load could also be caused by error frames. If a CAN-Messages gets destroyed by an error frame, the CAN-controller tries to repeat that CAN-Frame, which also increases the bus load.
Regards,
Gunnar Bohlen
the max. busload of 70%..100% means that there is a message burst within the selected time intervall of 200ms.
You cannot select a "wrong" measure window, it depends on what yo want to see.
You can modify the measure window from very small to very large and look for the average and max. value. If the messages are equally distributed, then the average and max. value stay very similar. If you reduce the measure window to the minimum value you might see 100% max. busload for a short periode followed by a value smaller than the average for a longer periode. This means there is a message burst. If the average bus load is not too high this does not indicate a problem, it just helps you to get more information about the message distribution over time.
Please also look for the error rate. The peak bus load could also be caused by error frames. If a CAN-Messages gets destroyed by an error frame, the CAN-controller tries to repeat that CAN-Frame, which also increases the bus load.
Regards,
Gunnar Bohlen