The RDC-ring, a fault-tolerant, decentrally controlled and event driven fiber optic communication network

Nowadays, the tasks of industrial automation of the office and of technical systems become increasingly more diverse and complex. In particular one recognizes a strong trend towards the interconnection of computer aided, individual solutions for different applications in process control, industrial management, design and development etc. This situation requires the reliable powerful and economic interconnection of distributed computer systems by means of local area networks (LANs). This paper describes a fault-tolerant fiber optic LAN with event driven, decentral and collisionfree access control. It is called the RDC-Ring. The design principles with respect to basic mechanisms influencing the performance characteristics and measures for fault diagnosis and fault tolerance are discussed. The protocol corresponding to the bottom two layers of the ISO Reference Model of Open Systems Interconnection is described in some detail with all services inclu ding the network management services. Then the main features of the fiber optic transmission system suitable for industrial application are discussed. Finally some results and experiences of serveral industrial control systems are reported on.