Fiber-Optic Local Area Network for Real-Time Telemetry

Abstract

For years, standard telemetry decommutators have proven the practical effectiveness and other advantages of using a data-driven (or data flow) broadcast bus for collecting, merging, and distributing continuous flow, real-time data. Bus length constraints have limited the use of the wideband broadcast bus to within a single chassis or closely mounted multiple chassis. Standard fiber-optic interfaces now make it possible to extend a real-time, greater than 5 million word/sec tag and data broadcast bus over kilometers at costs comparable to computer local area networks (LANs). Other advantages of this type of LAN include: no software protocol or handshaking, great flexibility in widely distributed processing and data base management, data security, and readily available off-the-shelf products. This paper discusses design considerations for conceptual networks, shows a sample design based on standard products, and suggests opportunities for product development for various types of network nodes. Also discussed are the implications to distributed processing and merging of real-time continuous data streams into the more blocked environment of general purpose computer processing and data base management.