BFF6206B NI-CAN Error

[Cimteker]

Hi,

My system has 4 PXI-8461/2 boards. It has been running fine for a few months. On the weekend my customer started getting error BFF6206B. I decoded this as "CAN bus problems (no ack) caused all communications to stop. This error corresponds to

CAN Bus Off state. Solution: Verify that the cabling is correct, devices are connected and

operational, and proper bus power is applied."

Any idea what night be causing it? From what I understand it is random (we have 4 modules tested at the same time with 4 PXI cards) and some modules are passing.

Thanks

CT. 

[ManLongAtNI]

Hi CT,

CAN devices sends data in packets called frames. Within this frame is an ACK (ACKnowledgement) slot. Any CAN controller that correctly receives the message sends an ACK bit at the end of the message. The transmitting node checks for the presence of the ACK bit on the bus and reattempts transmission if no acknowledge is detected. National Instruments Series 2 CAN interfaces have the capability of listen-only mode, but you have to make sure this is configured(typically not recommended). You error implies that it is not receiving an ACK from your device. This means as the solution indicates that the device is either not connected or functional.  

Regards,

Glenn