Soundcard acquisition without delay

[muhsin101]

Hello friends,

I have write a GUI in C++ and controlling it through the external signals, acquired using sound card in LabVIEW. Its working well but the I am facing two problems:

1> The soundcard acquisition in LabVIEW introduces a delay. It doesn't seem realtime. When I send the signal, it appears in LabVIEW after a edlay.

2> Acquired signal is compared with a threshold and an operation is done. Sometimes the threshold comparison doesn't work despite the signal amplitude is more than the threshold.

My VI is attached, created in LabVIEW 2010.

I want to do the realtime acquisition (with no delay) with soundcard just as DAQ devices do.

Thank you.

Muhsin Ali

[Brian_P]

The reason a delay appears in your data is because the VI that you are using collects the ALL the data first and then displays it.  You are comparing two different data types and so you are getting a boolean out, therefore your trigger is not going off is because you are not passing a boolean into your trigger or your case structure.  

[Brian_P · Accepted solution]

Disregard the messege about the boolean, I looked into and the boolean can be triggered using a dynamic data type.  But the reason you are getting the delay is because it first has to read all the data then it will display it.

[muhsin101]

Thanks, I got it. I minimized the delay in sound acquisition VI.

Regards,

Muhsin Ali