Cost effective computing unit redundancy in networked control systems using real-time ethernet protocol

Abstract

Designers of distributed computer systems have to take into account many requirements concerning the system operation and functionalities. In case of distributed real-time systems there are two characteristic features of great importance: reliability and temporal characteristics. High reliability level may be achieved by implementation of redundancy. However, every additional element in the system, also the redundant one, influences its temporal characteristic, one of which is the response time critical for the operation of Networked Control Systems. In the following chapter a system with cost effective computing unit redundancy operating in hot standby mode is described and analyzed from the point of view of its real-time operation. The possibility of implementation of synchronization routines between the computing units is also considered.