Research And Development On Distributed Redundancy Protocol Switch

Nowadays, as the Ethernet being used more widely in industrial control field, the real-time and determinacy of the communication has been greatly raised up. However, the reliability and availability of the network has not been carried out in-depth study, and the can not meet the availability requirements of the Industrial Network.Thus, IEC workgroup has been standardizing High Availability Automation Network, in which IEC 62439-6 (Distributed Redundancy Protocal-DRP) is a high availiability protocol designed by China.Firstly, this paper analyzes the the communication and fault detection and recovery mechanisms. DRP has two faulty-detection mechanisms "Ring Check" and "Link Check", which lead to the system's high availability.Secondly, I consider the DRP ring topology network as the research model, and propose the hardware and the software of the DRP switch, and carry out the design. This paper has several creations as following:(1) Design the "ports self-switch" mechanism, which can not only avoid Broadcast Storm, but also ensure the network recovery after failure quickly. (2) Create a "self-configuration function" based on the equal roles of DRP switches, which can eliminate the artificially configuration work. (3) Provide one kind of algorithm to calculate the time required for fault recovery from detection based on several parameters, including DRP circular network period, numbers of switch devices, datagram processing time, etc. (4) Establish "a model of DRP fault detection and recovery", which reflected the relationship among the stability of DRP control system, the number of switches and the probability breakdown of switch.Finally, I validated the recovery time and PTP pricision with the HW&SW platform, and verified the stability of DRP by the Matlab simulation test platform. The subsequent analysis results indicate that the DRP network has high availability and can be up to the mustard of the industrial control.