Hey Taipei,
This basically means that the utility was not able to receive the messages that it was transmitting. The first thing you should do is open up Measurement and Automation Explorer and find the CAN device under Devices and Interfaces. Try running the Self-Test to verify that the hardware is working correctly.
Next, open up the properties for both of the CAN Ports to verify that the settings are the same.
Finally, you will need to check your wiring. This is where most people have problems. The wiring will differ based on whether you are using a high-speed CAN device or a low-speed CAN device and whether you are using an internally or an externally powered bus. Make sure you pay very close attention to the wiring in the user manual (Chapter 4).
http://www.ni.com/pdf/manuals/370289g.pdf
If you are using a Series 2 PCI-CAN card with a DB9 connector you should connect 2,3,7,9 from one port directly to the other port and you need to connect a 120Ohm resistor from pins 2 to 7 on both ends of the cable.
If you are still having problems try calling our support and we can help walk you through the setup.
Joshua P.
Application Engineering
National Instruments
