The Delta DD series elevator door-control drive is an intelligent drive with outstanding features. These include a modular design for easy removal and installation of terminal blocks, a safety power switch and a built-in digital keypad for quick operation control. The drive has four control modes for opening and closing doors. The distance-control mode is a sensor-free system with an encoder which counts PG pulses to detect the position from the speed. The speed-control mode uses sensors to control the door opening and closing actions. The multi-step speed control mode generates a smooth door opening-and-closing curve using PLC control. The Delta DD series elevator door control drive provides a complete solution for elevator door control.