Hi,
NI-VISA 3.0 is the only driver in LabVIEW that would give you access to an USB device. You would probably use NI-VISA USB Raw mode.
To use the VISA driver you need to know in detail how the device works and how to program with USB. There isn't too much documentation, but if you are clear on those two things it should be easier to get familiar with the NI-VISA API.
You'll need the USB specification (www.usb.org). Also check the NI-VISA Programmer Reference Manual
Hope this is what you are looking for.
DiegoF
National Instruments.
