Remote handling of TEXTOR diagnostics using CORBA as communication architecture

At the Forschungszentrum Julich, an upgrade of the existing distributed sys tem for data acquisition (DAS) at the fusion experiment TEXTOR94 is under d evelopment. DAS is currently restricted to VAX/VMS and DECNET based communi cations, but it is planned to add UNIX based systems, and to open the local network for an improved wide area network access for remote operations. Th erefore, the DAS system is to be equipped with a suitable client/server int erface, which is able to cope with the various computer platforms and opera ting systems involved. For this purpose, the common object request broker a rchitecture (CORBA) will be used. CORBA is an object oriented, standardized architecture for distributed systems, which provides a high degree of modu larity in software design and allows for flexible implementations. It is to act as a connecting link between the existing system and new extensions. I n order to provide the desired client/server functionality for the data acq uisition tasks, the components of the system (diagnostic, database, etc.) a re modelled by CORBA interfaces. Processes for diagnostic control and data readout in the existing OpenVMS systems are aimed at to be accessible by CO RBA server implementations. The corresponding client implementations will b e developed for the operating system platforms most frequently used at TEXT OR94. Communication between clients and server will be based on TCP/IP and are to be managed by CORBA. By this standardized way, remote control of dia gnostic instrumentation becomes possible in a multiplatform computer and wi de area network environment. At a later stage it is intended to integrate t he system into a 'virtual control room' environment, which should enable th e participation of cooperating institutions in the full experimental progra m of TEXTOR94. (C) 1999 Elsevier Science S.A. All rights reserved.