A New Evaluation Method of Communication for Distributed Control

Distributed systems are relying more heavily on event-triggered system architectures such as UML and IEC 61499. Existing communication protocols can support the high-level communication within these systems, but there is contention as to which low-level protocol to use, or if any exist that meet the requirements of being event-triggered and hard realtime. This paper presents a new way to measure communication performance. The goal of the new measurement method is to stress the necessity that a system be both efficient and fair. This is illustrated by comparing three communication strategies; controller area network (CAN), time-triggered CAN (TTCAN), and alternating priority CAN. The first two represent the extremes between event-triggered and time-triggered communication strategies. The third is introduced to illustrate the benefits of the new measurement technique