A Framework for Process Automation Systems The Telegram Pattern

Frameworks are considered as a fundamental base for building powerful applications in object-oriented systems. In connection with design patterns, they provide an architectural guide for frequently appearing problems. Although, frameworks and design patterns can be regarded as state of the art in modern Software Engineering [5], they have not made their entrance to the industrial market, yet. Many process automation systems [2] are still developed with traditional programming languages like Fortran or C, which restrict the reuse of software to a low level, whereas object-oriented techniques allow to reuse the whole logic of a system. This paper presents a part of a framework for process automation systems [4], which has been developed in the course of an EU-project. It deals with the difficulties in telegrambased communication when telegrams (data streams) are transferred between different platforms and converted to the data format of the target system. The problem is modeled by a new design pattern the Telegram Pattern. The Telegram Pattern has been implemented with C++ and the CORBA [3] implementation Orbix. Its applicability within the framework has been validated by tests under realtime conditions at a hot rolling mill in Austria. It fulfills the requirements efficiency, flexibility, adaptability, reuse and portability and can henceforth be considered as a platform for the development of future process automation software.