NI-VISA USB Device not seen by MAX

[Val Brown]

I'm no wizard when it comes to device drivers. Thankfully I essentially stopped dealing with that kind of "low level" coding about 20 years ago. But now I've got a really intriguing situation that just doesn't make any sense.

I have a device that I communicate with -- in XP -- using VISA Read/Write operations. In XP it is enumerated twice once to device.sys the second enumeration to niviusbk.sys (this changes the PID from 1104 to 1124). I've used the Wizard to create INF files, both for XP and Vista and I also have a hand coded INF from the manufacturer. All works well in XP but in Vista, things get ugly.

I can install using the device_vista.inf generated by the wizard but, even though the device appears in Device Manager as "NI-VISA USB Device", neither MAX nor VISA Find Resource.VI can find it. I suspect there is some issue with the double enumeration under Vista but the curious part is that the INF supplied by the manufacturer does work under Vista (including the double enumeration) when I use their deviceUSB.sys instead of niviusbk.sys along with their C++ built EXE.

How could a device show up in Device Manager, correctly enumerated (apparently!) as NI-VISA USB Device and NOT be seen by MAX of VISA Find Resource.VI?

It doesn't make a lot of sense to me but, then again as I said, I gave up coding device drivers and such about 20 years ago. Any help would be appreciated.

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