Abstract
A control system is described as a set of dynamic process variables such as temperature, flow and pressure. These are physical parameters and their values change with time. The primary function of the control system is to maintain the process variables within certain desired range. For this purpose, the control system has to determine the state of the process and its evolution in time. In the former case, the system reacts to external events, which occur at arbitrary instants whereas the latter takes decisions at well-defined instants in real-time. The main elements of a control system consist of the external process (which is also referred to as the controlled system), the measurement (that requires the conversion of dynamic process variables into useful information for the other control elements) and the control elements (which influences the external process by updating the steps taken by the controller). Sensors are responsible for measuring the process variables and actuators are the control elements. In a computer-controlled system, the measurements and set points are converted from analog-to-digital and from digital-to-analog forms with the help of A/D and D/A converters respectively. In a centralized approach, the algorithm is implemented on a single computer. Sensors and actuators are all connected to a central computer with the help of dedicated links. The following steps are performed.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Astrom KJ,Wittenmark B (1990) Computer-Controlled Systems: Theory and Design,., 2nd Edition, Prentice-Hall International.
Cheng, SC, Stankovic, JA(1998) Scheduling Algorithms for Hard Real-time Systems — A Brief Survey,., Tutorial on Hard Real-time Systems, IEEE Computer Society.
Discrete Event Dynamic Systems: Analyzing Complexity and Performance in the Modern World, Ed. Ho, Y. C., Proceedings of the IEEE, Vol. 77, (1), 1989.
Kopetz, H, Ochsenreiter, Clock Synchronization in Distributed Real-time Systems,., IEEE Transactions
Norme Françcaise NF C 46–601 to C 46–607, “Bus FIP pour échange d’information entre transmetteurs, actionneurs et automates”, AFNOR Paris, France. An English version of these documents is available from WorldFIP, P. O. Box 13867, Research Triangle Park, NC 27709, U.S.A.
Phoebus llx, Spécifications Générales, Intrernal Report, EPFL-LIT, Swiss Federal Institute of Lausanne, Switzerland December 1990.
Prasad R (1993) Noubir,Static and Dynamic Polling Mechanisms for Fieldbus Networks, G., ACM SIGOPS, Operating Systems Review, Vol. 27, No. 3, July, pp. 34–45.
Prasad RV(1995) Modeling Periodic Fieldbus Systems,., Thèse NO 1405 (1995), Ecole Polytechnique Fédérale de Lausanne, Switzerland.
Raja P, NoubirV, Ruiz, Riese M, Decotignie (1993) Analysis of Polling Protocols for Fieldbus Networks., IFIP/WG10.3, Proceedings ICDDS, Palma de Majorca, Sept. 1517 pp. 139–155.
Turek J, Shasha D (1992) The Many Faces of Consensus in Distributed Systems, IEEE Computer, June.
Wakerly JF (1990) Digital Design, Principles and Practices,., Prentice Hall.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2003 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Raja, P., Noubir, G. (2003). A Synchronous Model for Fieldbus Systems. In: Mahalik, N.P. (eds) Fieldbus Technology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-07219-6_11
Download citation
DOI: https://doi.org/10.1007/978-3-662-07219-6_11
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-07284-0
Online ISBN: 978-3-662-07219-6
eBook Packages: Springer Book Archive