... switch, no need write code, never lost.8.Two ways to control projector by SERIAL PORT or ... if pull out VGA line of projector, the controller will alarm.10.Funtion of control computer turn ... , the fluctuate of voltage won't influence using central controller.Power of whole machine less than 4W, suit ... System end, safe and convenient.14.Two line controller of Hi-fi digital electronic volume, the microphone ...