I used a DT3100 series frame grabber with LabVIEW back in 1991 (before the IMAQ product line was introduced). I'm not sure if it was the 3155. It seems like it was a DT3185.
Anyway, the card came with a sample app and a DLL that you can call into from LabVIEW to access the card. Just read the manual, and examine the source for the sample app's header files to determine the proper function parameters.
If you need a manual, visit
http://www.datatranslation.com
support link. They have a product called DTLV now that may be helpfull to you too. I haven't used it, but it sounds like a library of VIs that you can use with their products.
