How to finding zero pionts of a waveform?

[Floyd He]

Hellow,

I am developing a programme, its output values observed from the waveform chart should be a Sinusoidal wave, but the exact function/expression is unknown. I would like to detect the zero point of the output sinusoidal waveform.

thanks a lot!

ps, I developed the programme in the constrol&simulation loop and I tried to extract the tone information like amp &freq from the outout but did not work...

Best regards,

Floyd

[altenbach]

If it is sinusoidal, it will potentially have an infinite number of zero crossings. Do you expect more than one?

How does your data look like? Can you attach an example?

Most likely, none of the waveform points will be exactly zero, do you want to linearly interpolate?

Is there noise?

[Floyd He]

Hellow, thanks for your reply!

As to the zero points, I just need two of them. I also noticed there won't be exactly zero and thought abour linear interpolation, but I don't know how to implement it,

There is no noise and just a pure sinusoidal waveform. Actually I would like to extract the frequency and amp info from the waveform, however extract tone information VI seems not working in control and simulation loop. Finding zero points and then calculate the period and finally get frequency is just am alternative.

I attached an example, in which I generated an sine wave with a "sine signal" VI, but in my programme the sinewave is actually unkonwn.

Best Regards,

Floyd

[altenbach]

Sorry, I don't have the simulation toolkit.