NI-VISA 2.x for Linux does not support PXI/PCI. Even the newly released 3.0 version (available for upgrade this week) does not support it.
I know that we have said we would like to support this functionality in a future release. We did not explicitly say it would be in the "next" release. Nonetheless, I am sorry if you feel misled. There just wasn't time for it. We will still consider it for future releases. Again, no promises at this time that it will be in the "next" version.
Dan Mondrik
Senior Software Engineer, NI-VISA
National Instruments