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Phase Difference Measurement by means of Digital Sampling

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lucien85

Electrical
Dec 5, 2011
1
A software is to be developed with Lab-View to record and compare two voltage signals simultaneously. The software shall be of the function to determine the time difference at the zero-crosses of the two signals with confirmed errors.
The analyzed results will be interpreted as the phase differences to do phase calibrations.

I am using 'Clark-Hess Model 5500-2 Digital phase standard' which generates 2 analog sine waves of the same frequency, connected to a PC with Labview via GPIB.
I am new to Labview and thus may i know:

1)How do i generate the waveform of the 2 sine waves concurrently on Labview from the hardwave mentioned above? The instrument driver is not available and thus the driver samples are not available to me. I had tried the DAQ assistant(through acquire signals>sine wave>voltage) but it fails to detect any instrument.

2)What sampling rate & resolution of the analog to digital converter hardware do i need? (I read somewhere and it vaguely says that it more practical to have 10x sampling rate of the signal measured, instead of 2x by theory.) Or, are there better/cheaper ways to digitize the 2 sine waves? Model 5500-2 has got a frequency range of 1hz-200khz.

3)Using Labview, how do i perform linear regressions at the zero crossings of the digital signals to measure phase difference? Do i need to incorperate 3rd party programs like Matlab to do this?

4)I read about using FFT for phase measurement, thus what others methods can i use in labview to measure phase difference of the 2 digital signals?
 
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