Application Of Xy Mode - UNI-T UPO2000CS Series User Manual

UPO2000CS series User Manual
XY Display Mode

7.2 Application of XY Mode

The phase difference between the two signals of the same frequency can be easily observed by Lissajous
method. The following chart gives the observation of phase difference.
Lissajous Graph
Since sinθ = A/B or C/D, theta (θ) is the angle between the two signals, the definition of A, B and C, D is shown
above. We can draw a difference angle θ = ± arcsin(A/B) or θ = ± arcsin(C/D). If the principal axis of an ellipse is in
π π π
quadrants I and III, then the phase angle should be in I, IV quadrant, in 0 to ( / 2) or (3 / 2) to 2 . If the principal
π π π π/2)
axis of an ellipse in II, IV quadrant, then the phase angle should be ( /2) to or to (3 .
In addition, if the frequency or phase difference of the two detected signals is an integer, the frequency and the
phase relationship between the two signals can be calculated according to the pattern in the following chart:
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