I'm not sure what the XW controller is, but if you're talking about the ZW controller, it's the same basic principle of a chopped sine wave for anything but minimum power. I don't have a ZW controller anymore, sold both of them. However, here's my bench supply, a Z750 brick and a Z-Controller. I start with the brick input to the Z-Controller and then the waveforms; min, middle, and max. All were done with a 75 ohm resistive load.
Z750 Brick Output
Z-Controller Min Setting Output (75 ohm load)
Z-Controller Midrange Setting Output (75 ohm load)
Z-Controller Max Setting Output (75 ohm load)