DPO6000
,
MPO6000 Series Digital Phosphor Oscilloscope Instruction V1.1
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4.1.2.XY Mode
In this mode, the oscilloscope changes the two channels from voltage-time display mode
to voltage-voltage display mode, where,the X-axis and Y-axis combination of XY display
mode can be CH1-CH2 or CH3-CH4.The phase deviation between 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.
Measurement Schematic Diagram of Phase Deviation
According to sin
=A/B or C/D (wherein,
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:
=
arc sin
B
A
or
arc sin
D
C
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