Design of fieldbus networks by bandwidth allocation scheme

Fieldbus is the lowest level communication network in the factory automation and process control systems. Performance of factory automation and process control systems is directly affected by the data delay induced by network traffic. Data generated from several distributed field devices can be largely divided into three categories of time-critical, periodic and time-available data. Since these data share one fieldbus network medium, the limited bandwidth of the fieldbus network must be appropriately allocated to the real-time, periodic and nonreal-time traffic. This paper introduces a new fieldbus design scheme which allocates limited bandwidth of fieldbus network to several different kinds of traffic. The design scheme introduced in this study not only satisfies the performance requirements of an application system interconnected into the fieldbus but also maximizes the utilization of network resources.