What is exactly error CanWarnCommStuff?

[e.c.]

Hello,
when i am transmitting a message from a microcontroller using a transceiver PCA82c250 and a low speed port (PCMCIA card) , i receive the CanWarnCommStuff message.
Does it mean that communication is correct and the problem is the message sent by the microcontroller or it can be another problem as the voltage in the lines?
Thank you
e.c.

[dhuff]

In theory this error means that the stuff bit(s) are wrong. Basically stuff bits are handled automatically by the CAN chip, added to break up long strings of bits all with the same state. (I am sure we could go on a long time here about how stuff bits work, but I won't)

In reality, this error could be could be lots of things (bad cable, bad connectors, bad CAN tranciever, or noise) but you might want to take a look at the CAN termination. I have seen certain cases when the termination resistance in the CAN card needs to change if you use low speed CAN. Also make sure the CAN cable has proper termination at the ends, a reflection on the bus could be messing up the bus.

Look at Appendix E in the NI CAN user Manual "Cabling Requirements for Low Speed CAN"