Jeff, I understand that you want to write out of your USB-parallel, but it's not going to be as simple as writing to a normal parallel port. You probably received drivers with your USB-Parallel adapter that allows the adapter to appear as though it is a standard parallel port (like LPT2) under Windows. That is going to be the correct way to do what you are trying to do, as then you can just use it in a VISA write just like a normal port.
The other way, writing out the USB port, requires knowing the manufacturer's device ID, what sort of pipes they use for communication, and what sort of data the adapter expects before it will output a set of bits on the parallel port. Hope this helps. Scott B. Applications Engineer National Instruments
