Container Crane Plc Control System Communication Problems

For a modern container port, the control system of the crane is comprised of not only the control of the single crane but also the surveillance and control of many cranes, the communication of which (the interior communication and the exterior communication) is studied in this paper.Combining with a concrete subject, the first chapter presents the communication in PLC control system in crane will be studied and why must it be studied.The interior communication is presents from chapter two to chapter four. By analyzing the hardware and software of PLC control system in crane, the second chapter makes clear that the objects of communication are PLC and inverters. Profibus is used in PLC control network in the subject. Chapter three analyzes the protocol of FieldBus and gives a representative Profibus topological. The fourth chapter makes clear that the communication of PLC and inverters is Profibus-DP mode in interior communication. In the chapter the data structure, the principle of parameters dealt with and parameters configuring of DP mode are analyzed.Chapter five is about the remote surveillance and control of many cranes (the exterior communication). Firstly, the network of the remote surveillance and control of many cranes is made. Then, some modes of remote data communication are presented. Lastly, from a concrete subject, some techniques in exterior communication are analyzed.Chapter six gives some conclusions about the interior communication and the exterior communication and points that some questions must be resolved as possible as early.