Implementation and performance evaluation of Profibus in the automation systems

Abstract

In this study, Profibus interface S/W is implemented on PC and embedded controller. In order to enable the Profibus interface S/W handles many application tasks and communication services, two kinds of real-time/multi-tasking operating system, CTask and OS-9, are utilized. Using the Profibus interface S/W, this study develops an experimental model of automation system, and evaluates the message delay in the user layer. Message delay is measured with respect to the changes of message length, message generation period and TRT(Token Rotation Time). The outcomes of experiment are compared with those of the simulation model which comprises only the physical and data link layers of Profibus. This study investigates the relationship between the message delay in the data link layer and the message delay up to the user layer. Based on the results, this study suggests some factors that should be considered when a Profibus-based automation system is designed and implemented.