I have doubt in measuring magnitude and phase of a waveform

[ULst]

I am not sure which block I should use instead of "Frequency Response Function"

[Shan]

Use "FFT Spectrum (Mag-Phase).vi". It's located in the same function pallete as the one you're using.

Tim

[LocalDSP]

It depends on what exactly you want to achieve. If you are interested in the transfer function between 2 signals, then, as Tim mentions, the FRF VI is the one to use. However I notice in your example that you only have one signal and that signal is periodic. Are you interested in the Amplitude or RMS value of that single signal as well as the start phase of it? If yes you should condiser using the Extract Single Tone Information also located in the same palette.

[ULst]

I am interested in extracting the magnitude and phase component of the product signal.Its not that I need at a single point. I want it to be all along the simulation time. As Tim talks about FFT(Mag-Phase).vi. I will try with that.
Thanks