IEC 61499 in a Nutshell

The IEC 61499 standard provides definition of various structures, such as systems, devices, resources, and various function block types, which allow for a component-oriented design of a program. This design approach resembles the famous object-oriented design paradigm, where the domain objects, e.g. sensors, actuators and devices, are modelled along with the automation logic. The execution of these structures depends on the adopted execution semantics, which determine the protocol of accepting inputs, processing signals, and generating outputs. In this chapter, we offer a brief introduction to some of the structures defined by the IEC 61499 standard and the various execution semantics that are commonly employed for their execution. The discussion on the advantages and disadvantages of each of the presented semantics motivates the adoption of the synchronous execution semantics proposed in this book, and described in detail in Chap. 4.