Even today, the roller shutter is first of all set goals, likewise the rolling door drive. This is in most cases, a worm with flange mounted motor and related control devices. The output speed is at 20. . . 30 1/min, because most of the power transfer to the roller door shaft or a chain reduction is used. A high operating frequency of the rolling gate requires a drive with 100% duty cycle (DC) are sufficient for normal operation, often 60% ED or less (see figure).