Period measurement

[stef31]

Hello,

I have a little issue with LabVIEW. I explain : I have a signal which is the sum of 2 sinusoidal signals. The goal is to capture the period of the resulting signal , characteristic of beat phenomenon.

But this signal is composed of a shortest signal and when I tried to measurated it the vi send to me the period of this little signal and not the period of the beat frequency.

I wonder if there is a mean to measure the period of the largest signal ?

Thanks for your help

[brucekr]

Just thinking out loud, but wouldn't a simple FFT give you each of the components and amplitudes?

[Paolo_P]

Hi,

What signal do you want to analyse on your bmp file.

If you want to get the envelope of the signal, you can use the Hilbert transform

http://zone.ni.com/reference/en-XX/help/371361H-01/lvanlsconcepts/hilbert_transform_analytic/

https://forums.ni.com/t5/LabVIEW/Envelope-detection-using-hilbert-transform-labview/m-p/2780708#M817...

[LocalDSP]

A simpler alternative to the Hilbert-based envelop detection and following up on Bruce K' FFT suggestion, you could use the Extract Multiple Tones VI in the Waveform Analysis palette to find your two beating frequencies. The beat frequency itself is then the difference between the two found frequency values.