The IEC 61499 standard has been recently adopted to promote a more flexible development process in the control and automation domain. The standard mainly deals with modeling issues leaving a lot of model execution details open. Different research groups are already working for the development of execution environments for the defined component model, proposing implementations with different execution semantics. This paper discuss the semantics of the execution environment and presents two execution environments, which although independently developed share a similar view of IEC61499 execution semantics and are both implemented over RTAI (real time application interface), a real-time Linux-based platform.

Currently available tools for the development of the next generation distributed control and automation systems, adopt traditional architectural styles and do not cover the whole requirements of the development process. One of the major drawbacks of traditional engineering support systems (ESSs), which is extensibility, can be addressed by providing a public domain framework that can be easily extended. In this paper, a service-oriented architectural framework is adopted to provide the infrastructure for the exploitation of service-oriented computing in the development process of factory automation systems. Features required in the development process are implemented as Web-services and published in the public domain, so as to be used on demand by control engineers to construct their projects' specific ESSs. The infrastructure required to build a Web-service based ESS is presented. Specific Web-services are presented and the way that these services affect the development process is discussed. The need of a common field device model in the context of this approach is discussed and an ontology-based framework for such a device model is defined.

Methodologies, techniques and tools that currently support the embedded systems (ESs) development process prove inadequate for today's complex ESs. Adopted traditional architectural styles do not cover the whole requirements of the development process, with extensibility being the major drawback. Service-oriented computing is exploited in this paper, to define an architectural framework for a demand-led ESs development process. Features required in the development process are defined as Web-services, published in the public domain, and used on demand through semantic Web by developers to construct their projects' specific integrated development environment (IDE). The way that these services affect the development process is discussed with main focus on an ontology-based device modeling.

The IEC 61499 standard introduces the function block (FB) model to support the development of open, interoperable, distributed control applications (DCAs). Currently available engineering support systems (ESSs) as well as those under development adopt traditional architectural styles and do not cover the whole requirements of the development process of FB-based DCAs. However, the major drawback of traditional ESSs is that of extensibility. This problem can be addressed by providing a public domain framework that can be easily extended. In this paper an approach that promotes the idea of service-oriented computing in the control and automation domain, is described. A service-oriented architectural framework is proposed to provide the infrastructure for the exploitation of service-oriented computing in the development process of factory automation systems. Features required in the development process will be implemented as services and published in the public domain. These services can be used on demand by control engineers to construct their projects' specific engineering support environments.

The function block (FB) has been defined by the International Electro-technical Commission (IEC) as the basic construct for the development of reusable, interoperable, distributed control applications. Complete applications can be defined in the design level as networks of interconnected FBs. For these design models to be automatically converted to implementation ones, adopting the model integrated computing paradigm, an appropriate implementation meta-model should be defined We describe two alternatives for the implementation of FB design models. The first one adopts the straightforward transformation of the FB design model to a high level language (C+ +, Java) implementation model. The second approach utilizes UML-RT models as an intermediate representation towards the final implementation model. Both approaches support the dynamic re-configuration of the control application and exploit our extensions to the IEC execution control chart notation, to improve the expressiveness of the design model and the efficiency of the implementation one