How to acquire 3 phase signals

Greetings
I need to analyze three sinusoidal signals 120 degrees out of phase by nature including my version of LabVIEW 7.1 and the acquisition card I used is the Measurement Computing USB 1208FS. In principle the acquisition and display them individually does not represent any kind of inconvenience, the problem arises when I try to observe the three signals in the same waveform graph. At this point to run the test continuously (Continuously RUN) the signals lose their phase shift and this becomes variable along the process of signal acquisition occasionally taking its original phase shift (in Figure 2 shows how to vary the phase angle between the signals), just watch the same channel form using 3 distinct stages and the signal (in theory the same) is outdated fig 4. How can this problem be corrected? There is some appreciable time lag between data collection in the different channels that would alter the correct acquisition of the signals. You can correct varying the sampling frequency (rate) and the count?
I need the visualization and processing of three-phase signals in 'real time', because the amplitudes of these vary over time, which is why I run the program in RUN Continuously, otherwise the data acquisition would not be made continuously.

Please stick to your original post. You have now created three posts with the same question.

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How to acquire correctly three-phase signals (Problem with the gap between signals)

Greetings
I need to analyze three sinusoidal signals 120 degrees out of phase by nature including my version of LabVIEW 7.1 and the acquisition card I used is the Measurement Computing USB 1208FS. In principle the acquisition and display them individually does not represent any kind of inconvenience, the problem arises when I try to observe the three signals in the same waveform graph. At this point to run the test continuously (Continuously RUN) the signals lose their phase shift and this becomes variable along the process of signal acquisition occasionally taking its original phase shift (in Figure 2 shows how to vary the phase angle between the signals), just watch the same channel form using 3 distinct stages and the signal (in theory the same) is outdated fig 4. How can this problem be corrected? There is some appreciable time lag between data collection in the different channels that would alter the correct acquisition of the signals. You can correct varying the sampling frequency (rate) and the count?
Pd = vi attachment used for the acquisition
Thanks
Attachments:
figure 2.jpg ‏70 KB
figure 4.jpg ‏72 KB
3 channel.vi ‏388 KB

Duplicate Post
Cory K

How to calculate the phase difference between two square wave (acquired from two channel in one DAQ)

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Attachments:
method export signal.vi ‏21 KB
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Hi,
Have things changed over the years?
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Thanks in advance!

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Attachments:
without trigger.txt ‏5 KB
with trigger.txt ‏6 KB
Multi-Device Synch-Analog Input-Finite Acq-Analog Start_Claire_wDigitalin_12June2012 PTbridge.vi ‏196 KB

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"... after all, He's not a tame lion..."
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Regards,
Field Sales Engineer | National Instruments | UK & Ireland
Attachments:
NI_phase shift sine.vi ‏31 KB

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How to acquire 3 phase signals

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