DPO6000, MPO6000 Series Digital Fluorescent Oscilloscope Product Manual V1.3 YT dual window display mode XY mode In this mode, the oscilloscope converts the two input channels from voltage-time dis- play to voltage-voltage display. The X-axis Y-axis combination can be CH1-CH2 or CH3-CH4. The Lissajous method can conveniently measure the phase difference be- tween two signals at the same frequency. The figure below shows the measurement principle of phase difference. 29