How do I utilize the XY display feature on a DPO/MSO/MDO4000 Series oscilloscope?

The XY display format can be used to measure the phase relationship between two or more synchronous signals. This measurement technique involves inputting one signal into the vertical system as usual and then another signal into the horizontal system – called an XY measurement because both the X and Y axis are tracing voltages. The waveform that results from this arrangement is called a Lissajous pattern (named for French physicist Jules Antoine Lissajous and pronounced LEE–sa–zhoo). From the shape of the Lissajous pattern, you can tell the phase difference between the two signals. You can also tell their frequency ratio. The figure and video below both show Lissajous patterns for various frequency ratioses and phase shifts as well as demonstrate some of features on the Tektronix oscilloscope.