Design And Research On Intelligent Electrical Valve Actuator Based On MODBUS-RTU

With their continuous development, modern information technology and computer control technology are applied to distributed control and process control system, which is in dramatic growth. Excellent in industrial communication is the field bus. MODBUS is one of the popular field bus of current industrial network. By its advance and reliability, FCS is thought important increasingly.The electron actuator of valve, one of industrial control, is widely used in agriculture, mechanical industry, chemical industry etc. it is attended more and more for the feature of ability and easy. Now with the constituting of international field bus standard and the coming of the distributed and opened field bus control system, smart and bus is the important develop direction of the electron actuator of value.We often came up against the problem to put valve under control. In order to realize valve actuator which is intelligence and digitized networking, the valve actuator of our country is faced with upgrade of technology. It is the tread of modern industry. The subject is major scientific and technological innovation projects of The Economic and Trade Commission of JiangSu Province. The target of the project is developing the micro processor control system of based on MODBUS field bus, which is the independent intellectual property right.The emphases of this paper is the design and research the hardware and software on intelligent electrical valve actuator base on field bus (Modbus protocol) to replace PLC controller. First, using Freescale MC9S08GB60 MCU, which have strong function, to replace former PLC controller. Second the theories of the absolute encoders and the relative encoder is introduced. The relative encoder is used measuring the position of valve. The interface hardware and software of encoder is designed and described.Third on the basis of intelligence, the paper also discuss the application of industrial field bus MODBUS RTU. Through analyzing the hardware and software components of MODBUS RTU-bus and the MODBUS - RTU communication protocol, ultimately the MODBUS RTU-bus has been applied to the valve controller. It has a profound significance not only because of its lower costs, smaller size, but also developing the own proprietary electric implementing agencies.The article also used a famous Chinese configuration software -Kingview (KINGVIEW) to develop a friendly interface, in order to achieve the long-distance communications with the implementing agencies.Tests found that the valve operation in good shape, and with the actual requirements. The paper provides a reference for domestic related fields.