SubVi DAQ values not updating Main VI

[Boldy]

Hi there, I'm in need of some urgent help as I have already wasted a couple days on this problem. I have a requirement to do some filtering on a Data Aquisition VI (which was written by someone else, please don't flame me for messy code!!!). I used the standard Chebyshev Filter VI, and I want to get rid of some harmonic distortion. Attached is the VI with a comment where I inserted the two filters.

The VI grabs analog signals on two channels, when I run the VI standalone it works fine, filters no problem. When I included this VI in my application it seems to grab the data ok, but doesn't filter it!!! I use the sub vi to do swept sine stuff, so it is called lots of times, within the execution of the program.

Could some one please help?

Thanks
Boldy

[KileenC]

Hi Boldy,

If I understand correctly, you are using the Acquirewaveform Outputwaveform DAQ.vi as a subVI. When called alone, this VI works as expected with the proper filter output. However, when used as a subVI in another application, the output of the filter is not the same. Is this correct? If so, here are some suggestions.

How are you passing the values of the filter output from the subVI into the top-level VI? I only see 3 output terminals on this subVI (Actual Scan Rate, Output Array, and Actual Update Rate). You will want to pass the output of the filter VIs using the output terminals of the subVI. Since your subVI seems to have all the terminals filled, you might want to consider using clusters to bundle some of your input/output data together.

Hope this helps. Good luck.

Kileen