RIGOL DS6000 Series - Manual (Page 75)

3 To Set the Horizontal System RIGOL
DS6000 User’s Guide 3-5
X-Y Mode
In this mode, the oscilloscope automatically turns on all the four channels (CH1-CH4)
and the screen is divided into two coordinate areas, where, X1 and Y1 track the
voltages of CH2 and CH1 and X2 and Y2 track the voltages of CH4 and CH3.
The phase deviation of two signals with the same frequency can be easily measured
via Lissajous method. The figure below shows the measurement schematic diagram
of the phase deviation.
According to sinθ=A/B or C/D (where, θ is the phase deviation angle between the
two channels and the definitions of A, B, C and D are as shown in the figure above),
the phase deviation angle is obtained, that is:
θ=±arcsin (A/B) or ±arcsin (C/D)
If the principal axis of the ellipse is within the quadrants of I and III, the phase
deviation angle obtained should be within the quadrants of I and IV namely within
(0~π/2) or (3π/2~2π). If the principal axis of the ellipse is within the quadrants of II
and IV, the phase deviation angle obtained should be within the quadrants of II and
III namely within (π/2~π) or (π~3π/2).
II I
III IV
A B
C
D
The signal must be
centered horizontally
III IV
II I