ni-visa and usb firmware development

[Skiko_Vienna]

Hello! I'm working on the developement of an USB device reading sensor data received by an rf interface. To avoid writing my own driver and dll's I want to use the VISA driver. I read the article in the knowledge base ("How Can I Communicate With a Device Using NI-VISA USB RAW Mode?") and looked over the 2 Nuggets for using VISA-USB. I have an minimal firmware with a driver (libusb) working with WinXP professional so the electrical connection is ok. When I change the driver to the generated VISA driver I get a code 10 error message. (Device is unable to start). I only saw solutions that ended up using the original driver in LABVIEW instead of VISA but when I've control over the firmware isn't it possible to get it working with VISA? What are the minimalistic requirements for an USB-device to work with VISA? It looks like my own device is missing some sort of request and VISA stops working at that point. Grettings

[PhilipDeppe]

Hey,

do you know the following tutorial?

USB Instrument Control Tutorial

http://zone.ni.com/devzone/cda/tut/p/id/4478

This is a great tutorial how to use VISA-USB.

Cheers,

Philip

[Skiko_Vienna]

Thank you for your suggestion Philip. I followed the tutorial but I got stuck at the point where I plug in my USB device. It looks like the USB firmeware I'm programming is lacking some features needed for the communication with the VISA driver. It would be very helpful to know which requests the driver sends to the USB device to check my firmware against the requirements. I tried using a USB mouse with VISA and had no problems integrating it into LabView. Greetings