Why do I get XNET Error 0xBFF63008 When Writing to CAN Bus?

Updated Nov 30, 2023

Reported In


  • NI-9862


  • LabVIEW 2017 Full
  • LabVIEW 2017 Base
  • LabVIEW 2017 Professional


  • NI-XNET 17.0

Issue Details

I am using XNET to write CAN frames to my XNET card and I keep getting error 0xBFF63008 "A Write Queue Overflowed". Why am I getting this error and how do I fix it?


This error indicates that the writing queue for the CAN bus is overfilling, likely because the frames are not actually going out onto the bus. 

Troubleshooting steps:
  1. Ensure that the bus is powered if it requires power. It is recommended to use a breakout box .
  2. If possible perform a loopback test to ensure your device is operating properly.
  3. Ensure that there is a device "listening".
  4. Be sure to Start the XNET session. If Auto start is set to False, then you will have to manually start the XNET frames sending out on the bus.