Authors: Mohamed Khalgui, Kleanthis Thramboulidis
Addresses: Nancy Universite – LORIA, UMR CNRS 7503, France. ' Electrical & Computer Engineering, Software Engineering Group, University of Patras, 26500 Patras, Greece
Abstract: The IEC61499 standard proposes the function block (FB) model for the next generation of distributed control applications. This model defines the FB type to be the basic construct in this paradigm. A control application is considered as a network of interconnected instances of FB types. These applications can be executed on one device such as a multitasking programmable logic controller (PLC), but they are usually executed on a network of interconnected devices. In this paper, a methodology for the development and deployment of IEC61499-based control applications on a network of interconnected devices is proposed. The methodology is based on a hybrid approach that integrates the unified modelling language (UML) with the FB model; to semi-automatically generate the design diagram in the form of a network of interconnected FB instances. A heuristic-based approach is described to allocate these instances to the execution environment, so as to satisfy constraints imposed by this kind of applications. A formal description of FB design models is proposed and a formal approach is described to assign FB instances to feasible OS tasks of devices while considering temporal constraints. A running example from industry is used to demonstrate the feasibility of the proposed approach.
Keywords: IEC 61499; function block model; manufacturing control systems; real-time systems; assignment; allocation; real-time scheduling; distributed control; industrial control; UML; sequencing.
International Journal of Modelling, Identification and Control, 2008 Vol.4 No.2, pp.186 - 204
Published online: 03 Nov 2008 *Full-text access for editors Access for subscribers Purchase this article Comment on this article