RT Spectrum Analyzer and Fluctuating Signal reading

[kelOb]

Hi There,

I am just wondering if anyone can help me. I am quite new to LabVIEW. My first problem is that the input coming in from my cRIO is fluctuating. Basically my setup is thus: a cRIO, an NI 9205 module, a geophone. When I try to take RT data in and show on a graph it fluctuates. I have attached a printscrn of it. It appears like a sine wave.

My main question is, I am wondering if there is any way in LabVIEW to analyze an acoustic signal in RT with a spectrogram? I have looked around online and there seems to be ways of doing it but there are just videos and pages demonstrating the results rather than how to go about creating a RT spectrogram.

Perhaps someone might be able to point me in the right direction? 🙂

[LanxiZ]

Hi kelOb,

Spectrogram is a set of advanced signal processing functions which are quite complicated and cannot be used in real time VI because the determinism of real time application. Hence you will need two vis in your project: one host vi which will run in windows dealing with signal processing and one cRIO vi which run in the cRIO hardware only to acquire data. The bridge between the host VI and the cRIO VI is the network published RT FIFO, which is similar to a queue but can be used to transfer data between Vis.

Attached is an example project showing you how to analyse the RT data in spectrogram.

If you have any other concerns please let me know.

[kelOb]

Hi LanxiZ,

That's very helpful thank you! A push in the right direction, I'd have spent hourse trying to get it to read directly onto the RT 🙂

Many thanks!