Hello,
I just did a quick websearch (I searched for PLX LabVIEW at google.com) and found the following webpage:
http://www.sheldoninst.com/plx.html
They offer a LabVIEW driver that interfaces with their DLL that communicates with PLX chips.
I hope this helps you out with your application. Good luck, and have a pleasant day.
Sincerely,
Darren Nattinger
Applications Engineer
National Instruments