Here is a data sheet on the Magnum AGS which explains some of the functions.
AGS_data_sheet_revc.pdf
If old age memory serves me correctly, I read somewhere that the thermostat for determination of inside temperature is incorporated into the enable/disable/test switch. When the system kicks on for temperature it will run for the preset run time and then shut down. Although the generator will start based on inside temp, it does not shut down based on temp.
Not sure how much it would cost to add the system on to a coach. It is standard on most of the coaches with a residential fridge and inverter.