I want ot control a stepper motor from a usb to parallel convertor on a Mac with LV 8.5. How do I set up NI VISA for that?

[rayjrt]

My current efforts return errors like:

Error -1073807298 occurred at VISA Write in Parallel Exp.vi
Possible reason(s):
VISA:  (Hex 0xBFFF003E) Could not perform operation because of I/O error.

I have been searching for hours with no results.

[Sputnikrent]

Could you provide an NI-Spy capture? Also, could you post a screenshot of your VI so that we can advise on how to do this?

Have you tried using the LabVIEW shipping examples to communicate with the port? There are instructions on how you can do this here.

You can access the examples by starting LabVIEW and going to Help > Find Examples > Search > Enter "parallel" > Parallel Port Additional Data Register Inputs.vi