Here is a KnowledgeBase that seems to describe what you are trying to do. Note that with NI-CAN, you cannot run BusMonitor on a port that you are actively using in LabVIEW, but you can hook up the second port as a passive listener to monitor the bus.
FYI: NI-XNET 1.0, the drivers that support our new CAN and FlexRay interfaces allows you to monitor a port while you are controlling it in LabVIEW. You do need the new hardware (PCI-851x) to take advantage of the XNET features.
Can I monitor a CAN interface while controlling it with a C program (the C program is using the NI-Xnet library)?. I have Ni-XNET 1.6 and a PXI-8512 CAN instrument, I am getting this same error. I would like to characterize the performance of our product. I am using both ports of the card, and looping traffic around 2 ports on our product. I am contemplating writing the code in C myself to get the frames/sec etc, but it would be nice if the Bus Monitor could go ahead and tell me this info.
you dont need to "waste" another CAN hardware for monitoring outgoing traffic.
Just set the property Self Reception?
this specifies whether to echo successfully transmitted CAN frames into the read queue of the CAN Network Interface and/or CAN
Objects. Each reception occurs just as if the frame were received from another CAN device. For self reception to operate properly, another CAN device must receive and acknowledge each transmit. If a transmitted frame is not successfully acknowledged, it is not echoed into the read queue.
this feature is available for NI-CAN as well as for NI-XNET