Display multiple channels on waveform graph

[Alv]

Hello,
I would like to display multiple channels of acoustic data on one waveform graph. I currently have them separated and controlled by tabs inside a case Structure. I sometimes have run into DAQ error because I'm looking at 10 channels of 1/3 Octave data real-time. I woundering if I display all the channels on one waveform graph would I elimnate this error.

can anyone help?

[Philip_Courtois]

Hi Alv,

Your explanation doesn't give me any idea of what the issue is with your VI. Please submit your VI and information on what error you are receiving. Also, please provide us with information like how fast you are acquiring your data, what DAQ board are you using and so on.

With that information it will be easier for us to help you.

[Alv]

Philip,
I'm acquiring data at 44KHz sample rate and my frequency range is 0-20kHz (2 ni-4472 DAQ cards). Since I been using LV (off and on now for about a year) my application is still in the development stage. I tried including pics but could only include 1 at a time, so heres a copy of my vi for you. There is several things I'd like to figure out, I'm viewing data real-time and writing data to file. However, as I'm writing data to file I don't want the data to display in real-time (I think this is where my problem is). The other issued is when I've stopped writing data to file, the case structure outside the while loop opens the file and processed the data, however I'd like to see the data in the same display (waveform graph in while loop). Take look and give me thoughts.

R/Scott

[shahina]

Hello Alv,

To display the data in your case structure (outside the while loop) in the same waveform graph (inside the while loop), you can use local variables. Just create a local variable for the waveform graph you need, and wire your data to it from anywhere in your VI.

Which specific DAQ error are you getting when running this VI?

Good luck with your application!
Shakhina P.
Applications Engineer
NI

[Alv]

WOuld I wire it from the analysis vi in the case structure (outside the while loop, far right)? Also I'll have 10 of these, so should I index? or should I just wire them directly.

Scott

[Alv]

I've created an example of what you suggested with the trial version I have here at home. What am I doing wrong here?
thanks
Scott

[Alv]

I figured out what my problem was. You have been a big help. I'll apply your recommendations to my application. Just for fun, heres my vi.

thanks again.
Scott