Design Examples of Distributed Applications Based on the Use of >Synchronized Clocks
John C. Eidson, Randy Coverstone
Agilent Laboratories, Palo Alto, CA

Simulations of physical systems generally incorporate an explicit representation for time. However real time programs designed for measurement and control applications are generally based on message passing rather than directly on time. This paper discusses the design of distributed real time measurement and control systems that are based on an explicit representation of time. This time representation is provided by sychronizing real time clocks in each node of the distributed system.

We first review a number of techniques for synchronizing clocks that are appropriate for embedded applications. The use of synchronized clocks is illustrated by several examples from the area of test and measurement and motion control. Finally we discuss the use of simulations in the design of such systems.