USB DRIVER FOR IMAQ

[Brad]

Sorry I've missed out on all the good USB discussion.  Glad to hear you found the Simple Chinese fix...I have been meaning to update the web example with the latest DLL that has all the new languages.  As for distributing USB LV Applications, there's a much easier way that doesn't require anything special on the target computers.  Check out this thread where I mention how to do it:

http://forums.ni.com/ni/board/message?board.id=200&message.id=5987

You will of course still need to license Vision if you're using Vision functions, but as far as getting the USB driver to work, you don't need to install it, just copy the two DLLs and register one of them and then your exe will work.

Hope this helps,

Brad

[MarcelJ]

I've made an application using the IMAQ USB driver, but there seems to be a memory leak.
I also found an earlier post about this, but haven't seen a post that states it's fixed.

I need to switch between the acquire and snap mode to allow two modes. The whole application works fine, but it seems that every time I switch memory size increases. With a memory leak, all my work has been for nothing because my application would eventually crash.

How can I solve this ?

[Brad]

There is a bug, but I don't think it's going to be fixed anytime soon unfortunately (this is not a supported product and it doesn't get updated much).  The workaround is to not open/close the session repeatedly.  You can create the appearance of a snap/grab by opening the camera, doing a grab setup, and when they want to grab, calling grab acquire continuously.  When they want to snap, call grab acquire once.  When you are done with the camera and your application closes, close the session.  This way it is just open once during your application.  Sorry there's not a better fix, but for now this is what I recommend.  This means users won't be able to change the acquistion window on the fly (since this is set in the Init) unless they open the driver's popup window to set the resolution of the camera.

Hope this helps,

Brad

[MarcelJ]

Hi Brad,

This helps.

Since it's not official supported code, why not make this open source ?
This way I could fix the bug myself without having to look for workarounds or spending time writing my own code from scratch.

regards,
Marcel

[Silvia]

Hello,

I am having the same problem with the USB driver, just getting the error -1074396024 (system memory error), but in my case it appears the second time I run the programm!! I find it quite strange. The first time the program is working perfectly. I stop it, try to run it again and Error!!. I tried also with the "USB example.vi" that Brad posted some time ago, and I get the same result: first time ok and next time error. To make it work again I have to close Labview completely.

Any idea?

Thank you,

Silvia.

[Andrzej_R]

Hi,

I experience similiar problem with USB vision driver . When I run my test application multiple times it with crash with window pointing to problem in imaqdirectshowdll.dll. I use only one IMAQ init and IMAQ grab setup call and multple IMAQ Grab Acquire calls. The strange thing is that the failure is not always in the point of image acquistion. Looks like driver is runnig continuously on the background and will eventualy crash. I used IMAQ stop call but it had no effect. Closing test every time before second execution helps( It must purge driver from windows memory) but it is only temporary solution.

Andrew 

[I_K]

I'm using Finnish XPSP2, strings are attached below. It would be very nice to have a support for this os also. Thank you!

[brad.buchanan@ni.com]

Here's the updated DLL with Finnish support.  Let me know if you have any problems.

Thanks,

Brad

[I_K]

Thanks Brad,

didn't have any problems.

[lpj669]

Hi Brad,
    I have problem in getting images by my usb camera, I once have some programmes which could work fine in LV8.0, but these programmes are not available now in LV8.2,  what's more, after staring Vision Assistant 8.0 and acquiring images through usb camera,
the system display a message "incorrect settings for the camera". I think that there maybe have some small bugs in NI-IMAQ for usb camera, as it is not support simplified Chinese language version OS so well.
    According thread of page 2 and 3 of the topic, I redownload the DLL -----USB Foreign OS DLL provided by NI and run a sample program, an error message pops up, it shows that x55 x63 xb7 x83, the screenshot is attached as follow.
    Looking forward to get the upgrade patch about simplified Chinese language version OS,LV8.2.
    Thank you very much!