A FLEXIBLE SOFTWARE FOR REAL-TIME CONTROL APPLICATIONS IN FUSION EXPERIMENTS G. De Tommasi * F. Piccolo ** A. Pironti * F. Sartori ** * Associazione EURATOM/ENEA/CREATE Dipartimento di Informatica e Sistemistica Universit`a degli Studi di Napoli “Federico II” ** EURATOM/UKAEA Fusion Association Culham Science Centre Abigdon, Oxon OX14 3DB, United Kingdom Abstract: JETRT is a framework of real-time software and simulation tools designed to help development of control systems in the JET fusion experiment environment. The main design choice is the complete separation of the target application from the hardware and plant interfaces. This architecture has been designed to maximize the reusability and to standardize the software development cycle of real-time control systems. Thanks to this design choice development costs have been reduced and even non-specialist programmers can easily contribute to a real-time project. JETRT also provides a set of powerful debugging and testing tools, some of them well integrated with the Matlab environment. This feature allows to reduce significantly the time spent on the plant for the commissioning of a new control system. Copyright c  2005 IFAC Keywords: Real-time systems, object-oriented design and programming, software tools. 1. INTRODUCTION JET tokamak (Wesson, 2000), though it was built more than twenty years ago, is still the world’s biggest pulsed operated fusion experi- ment, where several computers interact in order to perform real-time control and monitoring services (Lennholm et al. (1999), Puppin et al. (1996) and Sartori et al. (2003)). Tokamaks are the most promising confinement devices in the field of con- trolled nuclear fusion: their principal object is the containment of a thermonuclear plasma by means of strong magnetic fields. In such a complex environment achieving coding practice standardization and separation between the application software and its interfaces to the external systems, is the key to minimize develop- ment time and cost, and to maximize reusability and efficiency. JETRT has been designed to separate the al- gorithmic part of a real-time control application (User Application ) from the interface software (JETRTApp ), and to standardize the software development cycle. Portability among the desired computer platforms has been considered as well, leading to a further increase of code reusability and to a reduction of the debugging efforts. JETRT framework has been successfully used to develop and test many systems among the Real Time Data Network processing nodes (RTDN,