It may be desirable in some applications to make one of the zones have more priority for heating or cooling than the other zones.  This means that zone 1 will take control of the system to "satisfy" it's call before letting the other zones change the equipment mode.  If one or more of the other zones (2 thru 4) are calling for the same mode as the equipment, SmartZone will still open the damper to that zone... however, until zone 1 finishes it's call, the other zones calling for the opposite mode (heat or cool) will be ignored.  See below for wiring details or contact us with questions.