IMAQ USB Close leaves the camera open

[anotherStefan]

Hi,

I hope somebody can help me with that one. I have a DirectShow compliant USB camera, that I got to work with the IMAQ USB VIs. I can acquire images, enumerate the devices and get the options dialog. However calling the IMAQ USB Close VI does seem to have any effect. As the next time I try to call IMAQ USB Open afterwards I got error -1074396024 until I terminate the host process and restart LabVIEW again.

I am using LabVIEW 8.0, on W2k German

I also tried the samples (e.g. Grab.vi) provided with the same effect.

Running a tool that collects system debug messages (send via OutputDebugString) I got 'Export: Break Connect' coming from the IMAQ USB Close VI, but I also see, that the underlying DirectShow Interface doesn't receive any close call. Is there an Interface missing in the DirectShow interface (which?) or is this a bug in the IMAQ USB Interface (not very likely as a lot of guys seem to be happy with it)?

Can anybody help please?

Greetings,

Stefan

[ThSa]

Stefan,
below is an excerpt about the system requirements for IMAQ USB:
- Windows 2000/XP (English, Italian, Japanese, French, Italian, Norwegian, Dutch, Spanish/Portuguese, Russian, and simple Chinese)
- LabVIEW 7.0 or higher with NI Vision 7.1 or higher for the USB LabVIEW support.
- Vision Assistant 7.1 or higher for the USB Vision Assistant plugin module.

In general IMAQ USB is not supported but I will forward the information to R&D.

The following link povides other possibilities:
http://digital.ni.com/public.nsf/allkb/274a74a901399d0486256f32007295f9

Regards,
ThSa