The Design Of Automatic Control System For Pressed Plant Oil

With the development of economy, automatic control in all kinds of occupations of society has been used widely. This paper introduces a new automatic control system of pressed plant oil. The system adopts a hierarchy structure, which puts the PC as the host computer, the PLC as the lower computer, and uses the latest technology of the network control. The content of this paper mainly includes the design of the whole control system, hardware, software, the host computer control system and the network control system. The research for key technology of industrial Ethernet is included too.First , according to the process diagram and the requirements of oil squeezing process,this paper puts forward the corresponding control program, and then elaborates the hardware configuration of the system. The hardware includes the configuration of the PLC's module, the host computer's allocation and the hardware design of the communications. The main function of the lower computer is to complete the production control. In consideration of working environment and higher precision control of the system, the SIEMENS company's S7-200 series of PLC is chosen, which is of reliability to meet the control requirements. In the host computer monitoring system, we use the SIMENS company's configuration software WINCC to design the entire real-time monitoring of the oil squeezing process.The systems of the network control communication include not only between the host computer and PLC, but also between PLC and PLC is adopted. A new type of network control technology of Internet, it can constitute a perfect system of SCADA(Supervisory Control And Data Acquisition), which can collect the data and information, monitor the status of device automatically. And a number of the performances achieved the breakthrough in some key points, which are of obvious advantages. Industrial Ethernet is a new force of the control network. Smart module CP243-1 IT would be connected the S7-200 system into the industrial Ethernet,through OPC protocol and PC ACCESS software the data exchange between the host computer and PLC can be done easy.After the successful configure of the Ethernet module,it can implement the network communication between PLC and PLC, which achieves the goals of design.However, the real-time and reliability of the system need to be further studied.The experiments and debugging on the whole control system has been done. It shows that interface is perfect, operation stable and real-time better. This system not only can be used in the oil processing industry, but also play very better role in process control for other industries.