Research On Redundant Hot Standby Control System Based On Industrial Ethernet

In the traditional redundant fault tolerance scheme,there are often some problems and deficiencies,such as low communication rate,low data synchronization efficiency,long switching time between primary and standby and so on.Compared with the traditional fieldbus,real-time industrial Ethernet has many advantages,while there is relatively little research on the redundant architecture of real-time industrial Ethernet in China.This paper presents and implements a ring redundant control system with dual bus master station and programmable automation cotoller(PAC).The basic principle and fault detection method of industrial Ethernet ring redundant link are studied.This paper analyzes the mechanism of frame loss when the link topology changes,and adopts the method of delaying the establishment of connection and shortening the response time of link loss to reduce frame loss.The dual redundant hot standby bus master station is designed by using the parallel structure.By analyzing the master station state machine,the master station state synchronization method is designed to ensure the synchronous operation of the dual computers.This paper studies the feasibility of PAC as a bus slave,and designs the heartbeat detection and active and standby state switching method of PAC dual computer redundancy.In order to solve the problem of inconsistent data between the main and standby computers,combined with the characteristics of PAC programming system,a data synchronization method of single full synchronization and multiple catch-up synchronization is designed.In order to verify the feasibility of the designed redundancy scheme,an experimental platform is designed with zynq as the main control chip,and the key performance indexes such as communication jitter and frame loss rate when the link topology changes are tested.The main and standby switching time and data synchronization time of PAC dual redundancy are analyzed.The test results show that its redundancy performance can meet the requirements of practical use.