Functional Design for IEC 61499 Distributed Control Systems using UML Activity Diagrams

Distributed Control Systems (DCSs) are presently standardized by IEC 61499 that pro- poses the use of Function Blocks (FBs) to control automation process. Reusability and flexibility of the control software are achieved as one of the main factors that initiated the appearance of this standard. Meanwhile, it is important to make a con- troller system easy to design since market demands change rapidly. Consequently, a control strategy should be re-designable as fast as possible. This paper describes a method to design a system with the common functionality allocation approach based on the fundamental functionality of the sys- tem processes. By building generic FBs based on this approach it is expected that the design of a con- troller for a system can be easier, the software component can be reused, and configuration and reconfiguration of the system can be more flexible. For modeling the behavior of the FBs Activity Dia- grams of UML are investigated since they are based on Petri net semantics and therefore allow the transparent description of concurrent behavior. Finally, the implementation of functional design of the system is described to illustrate the advantages of using this approach.