Set Default Bit Value to 0xFF for J1939 in NI-XNET

Updated Apr 25, 2023

Reported In


  • PXI-8512/2


  • LabVIEW



Issue Details

I am writing a multitude of CAN signals via an XNET module. I've noticed that the undefined areas of the frames are populated with 0s, rather than 1s (0xFF) as defined in the J1939 specification. Is there any way to change that behavior on the XNET hardware/software?


In the XNET Database Editor, you can change the Application Protocol to J1939 for your XNET database. Afterwards, if any section of your frame is not defined by a signal, the value for that section of the frame will default to 0xFF. Signals with a value of 0 will still be written as a 0 onto the bus.

Additional Information

More information on J1939 implementation in NI-XNET can be found in the NI-XNET Hardware and Software User Help .