How to change FFT settings ?

I am analyzing a power system simulated on SIMULINK for which I need to use some FFT tool. Usually, the "Powergui" is used to get the FFT of a signal. However, when I use it I do not get specific frequencies that are present in the signal. The results display all the frequencies depending on the number of cycles I select and the frequency. Also, when I use the "power_fftscope" function, the fundamental frequency has been preset to 60 Hz; I want to change it to 50 Hz. Could you guys help me out in atleast one of the two problems mentioned above?

Answer 1

[Rashmil Dahanayake]

Are you using the Gui of the fftscope.

If so you can update the number of cycles and frequency as required. If you need only integet multiples of the fundamental, set number of cycles to 1.

In command line you, need to initially store fft results to a structure then modify the parameters(fundamental, cycles) prior to the second run.

[Sameer]

How do I store the FFT results? Can i use a MATLAB code to get the frequencies in this signal?