Remote handling of TEXTOR diagnostics using CORBA as communication architecture

At the Forschungszentrum Jülich, an upgrade of the existing distributed system for data acquisition (DAS) at the fusion experiment TEXTOR94 is under development. DAS is currently restricted to VAX/VMS and DECNET based communications, 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. Therefore, the DAS system is to be equipped with a suitable client/server interface, which is able to cope with the various computer platforms and operating systems involved. For this purpose, the common object request broker architecture (CORBA) will be used. CORBA is an object oriented, standardized architecture for distributed systems, which provides a high degree of modularity in software design and allows for flexible implementations. It is to act as a connecting link between the existing system and new extensions. In order to provide the desired client/server functionality for the data acquisition tasks, the components of the system (diagnostic, database, etc.) are modelled by CORBA interfaces. Processes for diagnostic control and data readout in the existing OpenVMS systems are aimed at to be accessible by CORBA server implementations. The corresponding client implementations will be developed for the operating system platforms most frequently used at TEXTOR94. 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 diagnostic instrumentation becomes possible in a multiplatform computer and wide area network environment. At a later stage it is intended to integrate the system into a ‘virtual control room’ environment, which should enable the participation of cooperating institutions in the full experimental program of TEXTOR94.