Research on Safe Communication Architecture for Real-Time Ethernet Distributed Control System

Abstract

With the penetration of real-time Ethernet in industry, the mechanism of CANopen protocol based on real-time Ethernet (COE) has been widely used in various distributed control systems. However, due to some defects of the existing COE mechanism, the functional integrity and security for communication could not be guaranteed. Thus, Safe-COE architecture is designed in this paper. First, safe communication problems in systems are analyzed. Then, based on the Security and Safety Modeling (SESAMO) method, safe building blocks for communication are designed and combining these building blocks with Safe-COE mechanism, a kind of Safe-COE communication architecture is proposed. Finally, communication performance is tested based on this architecture. The results show that based on the general Ethernet MII bus interface, the minimum communication cycle could reach 125 μs , and the minimum synchronization accuracy of peripherals control could be about 100 ns. Moreover, the formal modeling method is used to verify the safe integrity of this architecture. The results show that the architecture could meet related safe requirements of attack protection, data validation, disconnect monitoring, and state switching. Currently, there is no safe communication architecture for a distributed control system that could fully meet related standards and consider both functional safety and information security. It could provide a theoretical basis and solution for safe communication in the distributed control system.

Keywords

• COE communication protocol
• distributed control system
• formalized modeling method
• real-time Ethernet bus
• SESAMO building blocks