How can I output frequency readings of my signals using FFT?

[Keith Tan]

Hi there, I need help in regard to the topic stated.

Currently I have accquired a sine wave with frequency that vary, using one of the accquistion card by NI. I had converted it to a digital signal so that labview can read it. Now, I will like labview to output the measurement of the frequency.

For example : sine wave of 5KHZ is accquire ,  labview will use FFT to convert time domain to frequency domain, and then output the frequency of the sine wave, in the case, 5KHZ.

What function block should I be using? I had explored the function blocks of all FFT. Most of them output either real FFT, complex FFT, magniture or phase. But none of them output the reading of the frequency.

Maybe I had missed out some function block, so how do I go about output a frequency reading after using FFT?

Thanks a lot in advance.

[Baji]

After Converting your signal from time domain to frequency domain, u cant expect there is only one frequency component,they should have different frequency components according to your input signal.Use extract single tone information to get the output reading of the frequency.

[Coq_Rouge]

Hi

Goto help in the toolbar then select Find examples. Labview is shiped with tons of examples also many FFT examples