Hi,
The first thing that needs to be determine is exactly which driver are you using. I installed the LabVIEW 6.0 driver for the instrument and it didn't install the .c file. The .c file comes with Labwindows/cvi version of the driver.
It would also help if you could give me some info on the system. Are you using a GPIB or serial interface, OS, etc. Inlcude any information you consider important.
Diego F.
National Instruments.