Creating and controlling a sine wave

[texasstate]

I am a TA for Control Systems & Instrumentation at Texas State University. As the assistant I am required to assist students in their homeworks and projects. I have encountered a problem in assisting the students. How do I create a Sine Wave wit ha sampling frequency of 200 Hz? Obtain the power spectrum of the signal and change the sine wave frequency to 25 Hz. Determine if the resulting frequency is about the Nyquist frequency. Then increase the sine wave to 125 Hz and compare to the Nyquist frequency again.

[Karissa]

There is an example shipped with LabVIEW 2009 called "Resampling a Waveform (continuous).vi" I think this vi will demonstrate what you are trying to do. Change the sine wave frequency using the frequency control in the Test Signals (A) box and change the sampling frequency by updating the output rate control in the Output timing box. You will then see the original waveform spectrum at the original sampling rate (Fs) and the re-sampled spectrum will be shown in red so you can see the shift.