canbus error

[gems008]

We are using Ni_CAN card to talk with our device, most time is works, but sometimes we got error" 0x3ff6206B" which means "CAN bus problem detected (no ack), asked tio verify cable , connection and bus power, all of them are OK. What's the problem?
The device is functioning, we do not have any idea how to fix the problem.
Any info will be greatly appreciated.

James

[dhuff]

CAN messages sent out REQUIRE a second device to recieve the message, and acknoledge that the message came out with no errors. Check to make sure your device is not turning off or resetting the CAN chip.

[DirkW]

the warning you got means you have communication or transmission problems on the bus. Often this happens because of wrong termination within the connectors or wrong power on the bus. Check the termination. Use the formulas within the NI CAN manual for your board.
You can find the manual attached.
Additionally you can use the NI Spy to check your communication for warnings or errors.