Analysis: The width must meet: 0 < width < samples.

[Coq_Rouge]

Stil the same error? I tested it on my computer and it worked. Do you have a slow computer, and what kind of sound card do you use. Internal or USB?

[Coq_Rouge]

I think your problem is related to buffer overflow in the read sound card section. Then a buffer overflow occur, the soundcard  taskID becomes invalid. Try to disable the beep sound. As I think this is the source of your problem. You might consider putting the beep action in a separate loop. Or read more samples from the sound card on each iteration say 500msec. The sound interface in Labview is not the best piece of software done by Labview. Many consider the whole thing a bug. It is free 3. Part system that works much better. Or use the Labview 7.x sound system.

[Stergios]

Coq Rouge, your help has been decisive! I used "BEEP.WAV" outside the loop and everything worked just fine! I also change "PLAY sound file.vi" with "Sound output write.vi" with all the necessary setup VIs (Sound file read OPEN.vi, sound file read.vi etc..).

I have came to realize that indeed the SOUND library is quite problematic in LabView 8.5, but there are some ways around it..

Thank you for your help and time!

PS: sorry it took me so long to reply, there was a big strike here in Greece, and i did not have access to my university's computer..

[Coq_Rouge]

I have done a lot of complaining in this forum about the Labview sound system. I have had some accept for point of view. But the hard thing is to reach the correct people to talk with. Talking to a low level AE that do not realy care about my problem have not helped so far.

Then I need to use sound IO with better performance I use this http://www.zeitnitz.de/Christian/waveio?PHPSESSID=q0al6mdue38netcpojdikau8d1

It is free to download and use in non commercial application. The funny thing is that the sound system used in Labview 7.x can in many ways outperform the 8.x/9.x sound system. In some cases the this system is installed with newer versions of Labview but not put on the palette. Look in the

...\National Instruments\LabVIEW xx\vi.lib folder for a folder named sound.

[Stergios]

Oh, i had no idea there was such an add-on! I knew of www.zeitnitz.de because of their Soundcard Oscilloscope (http://www.zeitnitz.de/Christian/scope_en?PHPSESSID=q0al6mdue38netcpojdikau8d1) but had no idea they did this also...
Great site, thank you for the advise!
It's true, "Sound" is messed up..