Siemens plc for safety door systems
The customer’s design requirements for the safety door system are 20 hours a day, the minimum opening and closing cycle is 120 seconds, and the minimum service life is 1 million opening and closing cycles, which puts high requirements on the reliability of the electrical control and drive system.
Applications of Siemens plc products, technologies or solutions
After extensive communication with the customer, Siemens plc adopted a modular installation electrical control system to minimize construction time. Based on decades of experience in elevator door control, Siemens has developed the controller AT-EB and driver AT18S for the application of subway safety and screen door systems, combined with the existing SIMATIC S7-400H redundant Siemens PLC system and WinCC human-machine interface system. It provides customers with a completely open Totally Integrated Automation (TIA) platform.
Based on this platform, customers can apply their years of engineering experience accumulated in the screen door security door industry to the Siemens system, so as to form a system with the customer’s own intellectual property rights, to maximize the localization of the system development and subsequent low maintenance costs.
Design details
First, each security Door requires a Door Control Unit (DCU) for individual control. Siemens plc provided a dedicated AT-EB controller and two AT18S DC drive systems to build the DCU. AT-EB controls the two AT18S drives by communication, while AT-EB is also connected to the upper S7-400H Siemens PLC as a PROFIBUS DP slave station. In this way, S7-400H Siemens plc can monitor the working status of all security doors on the station, read and write the operating parameters of opening and closing doors. According to the operation requirements of the safety door, the AT-EB and AT18S realize the important safety protection functions such as closing the door when encountering resistance clip, infrared when encountering resistance detection, opening the door when encountering resistance protection, and emergency manual unlocking.
Secondly, in the process of normal operation, the security door system needs to get the opening and closing instructions from the signal system, and feedback the current status of the security door to the signal system, and also needs to report the status of the security door to the station comprehensive monitoring system in real time. Thanks to the openness of the Siemens TIA platform, the interconnection between the security door system and other systems in the subway has become extremely simple, and it is only necessary to add the corresponding modules in the S7-400H redundant Siemens PLC and do simple programming, so that information exchange methods such as safety relays, TCP/IP communication and Modbus communication can be realized. The data consistency of the Siemens TIA platform also guarantees direct access to the status of each safety gate in WinCC and S7-400 redundant Siemens PLCS without the need for complex setup and programming, greatly simplifying the customer’s development efforts.
In addition, unlike other subway shield door security system suppliers, Siemens only provides core electrical control components. Mechanical components and other auxiliary electrical components are designed, purchased and manufactured by the customer.