Center-opening VVVF synchronous door operator: width of opening is 800mm?1100mm Adopt round-arc claw synchronous belt and connect with synchronous door vane and hanged plate. The transmission of the variable frequency motor drives the synchronous belt, door vane and hanged plate to accomplish the opening and closing of the door. The synchronous door vane keeps clamping the door lock roller of the landing door during the course of opening and closing of the door, and make car door move synchronously with the landing door. The inspection and orientation method of left and right hanged plate of the door operator are accomplished through bistable switch, photo-electric code disk and photo-electric encoder. Control the opening and closing of the door automatically with the special Almeson variable frequency control system. It has the characteristics of simple transmission, high precise orientation and stable running, etc. The contact area of hanged wheel and track is small, low noise and reliable operation. There are two ways of installation for door operator, that is car frame installation and car ceiling installation. It is optional for the elevator manufacturers.