56F803 MSCAN correct bit timings @ 50 kbps

Hello all,

I'm having problems with our network running at 50kbps. Over a long
time (many hours or a few days) the MSCAN module goes dead and is no
longer communicating. The environment is pretty noisy, but the CAN
signals are not distorted. There are no CAN error interrupts, and the
error counter remains at 0.
What are the timings you are using? I've tried many different timings,
the best until now was CLKSRC=1, TSEG1 ( in the register),
TSEG2=7 (=6 in the reg.) SJW=1; the problem is that this sampling
point is not really CANOpen-Conform.
Can you please recommend me TESTED configurations at this speed?

BR,
George Start a New Thread

Hello George,

I recall having a problem on the 56F807 where the MSCAN module would go dead. It seemed to be directly related to EMI. I had a 100kHz square wave comming onto my board and going through a 74LVC14 to a timer input. When I removed that signal the problem would go away. I changed the 74LVC14 to a lower speed 74LV14 and the problem went away.

So I would recommend looking for sources of EMI in your system.

Pete

Hello all,
>
>I'm having problems with our network running at 50kbps. Over a long
>time (many hours or a few days) the MSCAN module goes dead and is no
>longer communicating. The environment is pretty noisy, but the CAN
>signals are not distorted. There are no CAN error interrupts, and the
>error counter remains at 0.
>What are the timings you are using? I've tried many different timings,
>the best until now was CLKSRC=1, TSEG1 ( in the register),
>TSEG2=7 (=6 in the reg.) SJW=1; the problem is that this sampling
>point is not really CANOpen-Conform.
>Can you please recommend me TESTED configurations at this speed?
>
>BR,
>George Start a New Thread