TECHNICAL ARTICLE A Simulation Study on the Performance Analysis of the Data Link Layer of IEC/ISA Fieldbus

Fieldbus provides real-time data communication among field devices in the process control and fac-tory automation systems. IEC and ISA recently approved the fieldbus standard for use in indus-trial control systems. The data link layer of IEC/ ISA fieldbus provides token-passing and schedul-ing services for data transmission. This paper ana-lyzes the performance characteristics of the IEC/ ISA fieldbus, especially the capabilities of the real-time data transmission and priority mechanism. In this study, a discrete-event simulation model of the data link layer of IEC/ISA fieldbus is developed. Using the simulation model, this study identifies the network parameters that influence the perfor-mance of the data link layer, and investigates the delay performance with respect to the change of the network parameters. Based on the simulation analy-sis, this study draws essential conclusions that should be considered in the network system design and operation of IEC/ISA fieldbus