User Manual

3 To Set the Horizontal System RIGOL
MSO4000/DS4000 User’s Guide
3-5
X-Y Mode
In this mode, the oscilloscope automatically turns on all four channels (CH1 to CH4)
and the screen is divided into two coordinate areas. X1 and Y1 track the voltages of
CH2 and CH1 and X2 and Y2 track the voltages of CH4 and CH3.
The phase deviation between two signals with the same frequency can be easily
measured via the Lissajous method. The figure below shows the measurement
schematic diagram of the phase deviation.
According to sin
θ=A/B or C/D (wherein, 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 quadrant I and III, the phase deviation
angle obtained should be within quadrant I and IV, namely within (0 to π/2) or (3π/2
to 2π). If the principal axis of the ellipse is within quadrant II and IV, the phase
deviation angle obtained should be within quadrant II and III, namely within (π/2 to
π) or (π to 3π/2).
II I
III IV
A
B
C
D
The signal must be
centered horizontally
III IV
II I