phase shift

[Daniel2903]

Hi guys,

I want measurement phase shift between two signals which can u see in attachments. Im using NI-USB 6008. Im labview newbie (and english too) so it's not going well. I tried use several methods some what I found on this forum. I want filtering input signal too (but I do not find good way). Do you like some of my way? Or can U advice my som better? thanks for any help.

Daniel

[johnsold]

Daniel,

From the image you posted it appears that your signal is not sinusoidal and is rather noisy.  Both make it more difficult to measure phase differences. The phase difference in the image seems to be small.  Do you know what the phase difference for that signal should be?

Please post the data.  With real data we can try to see what can be done.  One way to post data is to run your VI. When the data is displayed on the graph, stop the VI, and then go to the Edit menu and select Make Current Values Default. Save the VI with those default values and post that VI. 

Lynn

[Henrik_Volkers]

The extract single tone.vi should do the job. Even with the higher order harmonics and noise it should give reasonable results.

Capture 20 to 100 periodes and display them in a graph, go to Edit- Make current values default, save the vi and post it.