The Research Of Data Synchronization Cheme Based On S7-200 Redundant Controllers

Along with the industrial field devices use for a long time, improve the reliability of the system itself has been unable to meet the needs of customers, so the redundant technology was introduced into control system. As large PLC built-in redundancy function, micro and small PLC itself has no redundancy, which makes the micro and small PLC redundancy system could satisfy the customer demand situation have to use more expensive medium and large PLC redundancy system, causing an increase in the cost. In view of this situation, this paper carried out relevant research of s7-200 PLC redundancy.In this paper, using the process control laboratory as the background, analyses the current development of PLC redundancy technology at home and abroad and the advantages and disadvantages of various industrial automation network protocol,concluded that the feasibility of data synchronization scheme research based on S7-200 redundant controllers. And then studied the working principle of s7-200 redundant systems, the redundancy required for the Modbus RTU protocol library modules are analyzed in detail, to master the using process of each module. In understanding s7-200 redundant system working principle, Performancing analysis of data synchronization in redundant systems,Combined with the theory of reliability from two aspects of reliability and life expectancy of the s7-200 redundant systems theory verification, comparison of s7-200 PLC CPU dual redundant scheme reliability is best.Finally it has carried on the application of s7-200 soft redundancy system. Finally,test shows that, this system can be applied to the occasion of the requirements of production technology is not high, attaches great importance to the stability of the system. The completion of this project for the application of micro, small PLC software redundancy in engineering played a certain reference.