Design Choices for Control and Data Acquisition in RFX

The concepts and the criteria for the updating of the Control and Data Acquisition of RFX are reported and discussed in the paper. The system fully exploits the new MDSPlus multi-platform approach, in particylar: its availability under most operating systems (OpenVMS, Unix, Windows, VxWorks), the mdsip communication layer, the new platform-independent, Java-based user interface. A new hardware platform now defines processors to handle locally data acquisition. The solution provides some new features to data acquisition, such as possible (quasi) real-time data display, local data processing and high level of distribution. CompactPCI has been selected as hardware standard, due to its high performance, lower cost and perspectives. A new timing system is under development. This is engineered in CompactPCI format but can be used together with the existing CAMAC-based system, as it is fully compatible. The control and monitoring system relies, as far as possible, on standards established in industrial automation, such as fieldbuses at cell automation level, and industrial versions of Ethernet at factory automation level. The SCADA system is maintained, but used in client/server configuration, allowing centralization of functions such as signal acquisition and storage and alarm handling, but remote display of the user interface. As the SCADA package runs under Windows, the communication layer makes extensive use of OPC (OLE for Process Control), an emerging standard in Windows-based automation applications.