NI-XNET has native support for J1939 as of version 15.0. You can download NI-XNET
through our website. Make sure the version of NI-XNET is compatible with your version of LabVIEW
(if using LabVIEW). You can find examples through the NI Example Finder in LabVIEW (Help >> Find Examples >> Search for 'J1939'
If you are unable to use version 15.0 or newer of NI-XNET, NI does offer the J1939 Transport Protocol Reference Example