Missing Sound Output VIs

[Slowpoke]

Hello all,

I'm trying to create a DLL that reads incoming sound data through my DAQ board and translates it for my sound card.  Unfortunately, when I run the control program (LabWindows), I get error messages saying that the LabVIEW Sound Output VIs are missing.  Do I need to add another library to my LabWindows project, and if so, which one?  If not, why isn't LabWindows (or the LabVIEW runtime engine, if applicable) finding the VIs in my DLL project library?

Thanks!

Slowpoke

[Riconquistiamola]

Hi Slowpoke,

Can you call your DLL in LabVIEW? If you can call it in LabVIEW it certainly sounds like a LabWindows/CVI issue, if not we should focus on the LabVIEW DLL creation problem.

Cheers.

[Slowpoke]

Hi Michael / Riconquistiamola (quite a nickname!),

Thank you for your reply.  I will try to call my DLL from LabVIEW and see what happens.

Slowpoke

[Slowpoke]

Hello again Michael,

Here I was thinking that I'd need half a day to learn to use the Call Library Function node, only to discover that it's all but automatic.  I love LabVIEW. 

To answer your question, my DLL works fine when called in LabVIEW.  (Maybe I should make my LabWindows app into a DLL and call *it* from LabVIEW...)

Thanks again,

Slowpoke

[Riconquistiamola]

Hi Slowpoke,

I'm glad you are able to call it in LabVIEW, but that raises other concerns. Is LabWindows running on your development computer or a deployment computer?

Also, can you provide a screenshot of the error messages you are receiving from LabWindows?

Cheers.

[Slowpoke]

Hello Michael,

LabWindows is running on my development computer along with LabVIEW.  Attached is a .png image showing the error window that pops up when I click on the VI's broken arrow icon.  "Configure for Sound.vi" initializes the DAQmx and sound card tasks.  "Sound Card Status.vi" is a functional global that stores and operates on the sound card task ID. 

Thanks!

Slowpoke

[Riconquistiamola]

Slowpoke,

I'm confused. In your first post you said the problem was with your control program, which is LabWindows. You mention "Configure for Sound.vi" and "Sound Card Status.vi" in this post. Is your problem with LabWindows or LabVIEW?

Cheers.

[Slowpoke]

Hi Michael,

Sorry for the confusion!    Guess they don't call me Slowpoke for nothing...anyway, let me see if I can clarify matters.

The problem is not with the control program, per se.  The problem only manifests itself when I call my DLL (created in LabVIEW) from the LabWindows control program.  When I call the DLL from a LabVIEW control program, the DLL works perfectly.  When I call the DLL from the LabWindows control program, the front panel of the called VI has a broken "run" arrow.  When I click on the broken arrow, I get the LabVIEW error message popup.  The LabWindows control program itself flags no errors. 

I mentioned those VIs only to offer some context for the problem, i.e., in case you were wondering what their functions and purpose were, since they appeared in the error popup; if I muddled things up for you instead, again I apologize.  Hope this is clearer! 

Thanks,

Slowpoke 

[Riconquistiamola]

Hi Slowpoke,

Thanks for the update. I think I confused myself on the last post, so no worries.

I attempted to reproduce this problem at my end but was unsuccessfully. Is there any way you can post the DLL (or a simplified equivalent) so I can try to reproduce the problem? This may be a bug in LabVIEW's App Builder, but I can't seem to reproduce it myself.

Cheers.

[Slowpoke]

Hi Michael,

You bet.  Attached is a .zip file containing the .dll, .lib and .h files of my DLL project.  If there's anything else I need to do, please don't hesitate to ask.

Thanks!

Slowpoke