2 function switch for ceiling fan and light?

[JDRoberts]

@ogiewon

These devices are not multi-tap capable devices.

Different kind of “tap.”

The Basics of Multi-Speed Motors

They are more like a classic dimmer module as they are simply controlling the amount of power being delivered to the fan motor in order to control speed.

no, they aren’t. Seriously, they are not anything like a classic dimmer module. The physics is completely different. They are not, repeat not sending power directly to the fan motor in order to control speed. I promise you, they are not.

See the FAQ:

Automating Fan Control--Don't Use a Light Dimmer!

Continuing the discussion from Fan Light Dimming - Aeon Labs Aeotec Z-Wave Micro Dimmer: Thanks for the shout. Yeah, basically you need to read the manufacturer’s directions for the fan, and check that against the manufacturer’s directions for the dim control. Rate controls For home use are usually either TRIAC or VFD (Variable frequency drive). A TRIAC controller varies only the voltage. This is what’s typically used for a dimmer light because that’s exactly how you make the light brighter, you give it more voltage. A VFD varies both the voltage and frequency. But more importantly in this context, is how the dimmer knows to turn itself on. The short answer is the dimmer switch itself, if it uses a TRIAC, is very sensitive to changes in the voltage, and basically it can get confused …

What they are doing is sending different levels of power to the fan controller Which is reading the level received and then selecting the matching tap point and the correct frequency and voltage.