fft of integer signal

[bcglaxer]

This is a pretty stupid question that I'm sure has a really simple answer, but for the life of me I can't figure it out. I have a source of 16-bit integer that I'd like to do a spectral analysis of and then, once I know a bit more about the signal, I'd like to filter it. However, all the analysis and filter .vis I can find have 64-bit real sinks and I can't find a conversion that work. Please help!

Thanks,
Brian

[altenbach]

If you connect it directly, you should get a coercion dot, but it should still work. What happens if you insert a "toDBL"?

Can you attach a simplified VI with some data?

Message Edited by altenbach on 07-27-2009 03:09 PM

[bcglaxer]

When I use a toDBL, suddenly the sinks become waveforms and it still doesn't work.

Attaching a simplified VI is difficult because the source is a .VI supplied by the manufacturer of a motor controller I'm using (Maxon Motors) that reads in data from the controller, and you're not likely to have it installed on your machine.

Thanks so much,

Brian

[JÞB]

We LIKE simple answers.  (I know, the tough one make us look smarter but......)

post some of your code as previously suggested.  Coersion dots are not demons.  But, if you don't know what the coersion is it is wise to avoid the "ugly" ones.

Hmmmm..... For LV Feedback I think I'll post a suggestion for differentiating the colors of "lossy" and "safe" coersion dots.

[j_osh_o]

I tried with AutoPower Spectrum.vi, and it results in a red coercion dot as predicted by a previous poster.  Can you make a test case like this one?  You probably don't need to post the whole vi to debug this problem.

[bcglaxer]

Here's a few screen shots. Am I just using the wrong VI? Where do you get that power spectrum VI?

Thanks,

Brian

[altenbach]

This is not plain LabVIEW. You seem to be using an add-on (e.g. simulation module) or something similar.

I am not familiar with this. Are you sure you have an array?

Message Edited by altenbach on 07-28-2009 12:55 PM

[JÞB]

You don't have an array!  what does the help show when you scroll over the wire with the wire tool?  (it should show the data type information)

[The_Chancenator]

Hi bcglaxer,

It looks like you are using the Control Design and Simulation Module.  Could you please post a snippet of your code causing the problem so it is easier to debug?

Thanks,

[bcglaxer]

Posting the code is difficult because for some reason I can't save duplicate heiarchies (there are .vis in my code from outside vendors  that you won't have). I've posted this problem elsewhere, but wasn't able to find a solution.

http://forums.ni.com/ni/board/message?board.id=170&message.id=409327#M409327

Thanks,

Brian