How does single lever control work in Rotax?

The single lever control is not done by the ECU but rather an external box that reads engine data via CAN.   The box is made by RS Flight systems.  The box electrically controls a hydraulic governor.  The pitch is determined by a formula designed by RS that looks at throttle position and other engine data and calculates a commanded RPM and sets pitch to match.

Alternatively there’s the Airmaster which reads RPM from the slip ring and changes pitch to try and match what the user preselects as the max RPM desired.  Slightly less “single lever” but more control, even full manual control if desired.  There’s no governor and the prop is controlled electronically through a slip ring   

In neither system is the Rotax involved in the prop control.  

Rotax® 912 iS Single Lever Propeller Governor System:

https://www.stockflightsystems.com/tl_files/downloads/emu912is/SFS_MT_Presentation.pdf

Rotax-Owner wrote:

Rotax® 912 iS Single Lever Propeller Governor System:

https://www.stockflightsystems.com/tl_files/downloads/emu912is/SFS_MT_Presentation.pdf

I read that before but it doesn't describe the formula. It just lists a few different engine parameters "and other data" and doesn't explain anything about how they are used to determine propeller pitch.

If it's not the Rotax computer that does it then I guess this is the wrong forum to ask so I'll try elsewhere.