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

Question

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between the signals), just watch the same channel form using 3 distinct stages and the signal (in theory the same) is outdated fig 4.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

Answer 1

Duplicate Post
Cory K