It’s a fairly simple concept: The Arduino in the prototype controller has ( in the software ) a virtual and simplified representation of the the attached radio. The program loop requests data ( frequency, then mode then S-meter etc ) - only one attribute on each successive loop. This data populates the virtual radio. The controllers rotary encoders can alter the virtual data, and when the controller detects a difference between the real and virtual radio’s attributes it sends “adjustments” to the real radio via the Remote port.