Research And Implementation Of PLC Networking Technology Siemens

With the rapid development of science and technology, the programmable logic controller (PLC) has successfully replaced the traditional relay control system, and been known as the three big props of modern industrial automated production which also including the distributed control system (DCS) and field bus control system (FCS). Control system used PLC shows the characteristics of the network, integrated, and gradually develops to the open system. Major colleges and universities have "Principles and applications of programmable logic controller" course as an important professional course of automation, electrical automation and electronic information related professional major. At the same time, universities have established their own PLC laboratory in order to increase the students’ competition in the society.While the presence of single type, insufficient quantity，scatter independently，lower versatility, integration and openness of equipments in the PLC laboratory of school can’t meet the requirements of PLC teaching task at this stage, the school carries on the transformation to the laboratory, buying Siemens series PLC and the network communication module that have a higher market share, building a powerful, widely used experimental platform for networking on the basis of the integration of the existing laboratory resources by taking this opportunity.The experimental platform is a control system including three-layer architecture of the field, control and management. The field device layer is divided into two parts, one part includes remote I/O device IM153-2, frequency transformer MM420equipped with DP communication card, PLC S7-200provided with EM277communication module, the controlled devices connected to the slave stations are traffic light experiment pendant, motor and belt conveyor respectively; The other part includes two remote I/O device IM153-4, to which the controlled devices connected are the PCT-II process control experimental device and a heating device. The control layer, composed of two S7-300，connects with the field layer through PROFIBUS-DP master-slave communication and Ethernet communication equipment respectively, to realize the control of field device. The management layer includes S7-400, WinCC monitor computer and touch screen, connects with the control layer via Industrial Ethernet, to achieve unified management of PC monitoring and data information. The platform takes the typical experimental pendant and complex process control laboratory’s equipments as the main objects, through a simulation of the running environment of typical process control system in industrial area, demonstrates and researches the construction and operation control of three level network control system. On this platform, communication experiment based on Siemens various communication protocols can be finished, the sequence logic control, motion control, and process control experiments can be completed in the network architecture as well.The platform has been set up and realized the process control of network integrating the field bus technology with industrial configuration technique through debugging, various types of loads can be operated normally in the PLC network; it also has been applied to the university’s teaching and training in PLC with good effect. The development of this platform not only meets the requirements of outstanding Engineers’ personnel training, but also provides an experimental platform based on industrial processes for teaching researches and developing applications.