How to get the time of the wave？

[weizhihua90]

hi，guys，I  got this wave，but i can't get the time of the wave by the program,

This waveform is only fixed in frequency，How to get the time of the wave？

[Gregory]

What kind of data is it? If it is a waveform (brown wire) you can use "get waveform components" to find t0 and dt.

If it is just an array of doubles (orange wire) you have to know the timing characteristics of your single in order to calculate it.

[GerdW]

Hi weizhihua,

How to get the time of the wave？

Why don't you just read the x axis values?

It should be either "time" (in a unit choosen by you) or it should be sample-index: multiply sample index with dt of your waveform…

[weizhihua90]

it is a waveform .The timing of the sine wave is random. I want to get the starting point and the end of the sine wave. I can't make it.

[weizhihua90]

The timing of the sine wave is random. I want to get the starting point and the end of the sine wave. I can't make it.

[GerdW · Accepted solution]

Hi wei,

calculate the differentiation of your signal: when it is unequal to zero you found your sine wave…

[weizhihua90]

Thanks.I'm going to learn how to get differentiation at LabVIEW,

[GerdW]

Hi wei,

I'm going to learn how to get differentiation at LabVIEW,

In the simplest case it's just the difference between current and previous sample.

You might think about a minimum difference because of noise in the signal…

[crossrulz]

I have done a similar detection using a "Moving RMS" calculation, which is exactly the same as a moving average except you use RMS instead of Mean.