Study The Control System Of Floating Dock Base Three Layers Control Network

This thesis studies the floating dock which is an important port repairing equipment and was used widely. In the past, the staffs control ups and downs of floating dock. However, with the development of automation technology, communication technology and control network, it is possible to control ups and downs of floating dock automatically. This thesis studies the automatic ups and downs control system of 8000t floating dock.The three layers industrial control network of floating dock control system is management layer, control layer, field device layer. The first is management layer which can achieve monitoring, optimize, display by WinCC; the second is control layer which can achieve automatic control of floating dock by PLC; the last is field device layer which can achieve the collection and translation of data etc. In general, PC enforce the management and monitoring, while PLC controller enforce automatic ups and downs control of floating dock. It is come true to communication between PC and PLC in ETHERNET and between CPU and ET200M of S7-400 PLC in PROFIBUS-DP.The follows are the thesis's main research contents. Firstly, according to the real hardware, configure the three layer network of control network. Secondly, analysis control requirement of control system and get the control flow-process diagram, then according to the diagram, design the PLC control program. In order to achieve automatic ups and downs control of floating dock really, the thesis studies valve's opening control carefully, and test in SIMATIC S7-400 PLC verify that the scheme is valid.In final, this thesis analysis software redundancy and hardware redundancy of control system briefly.