Design choices for control and data acquisition in RFX

Data acquisition and control were developed in RFX in the late 1980s, by adopting a split hardware approach based on the time characteristics of signals. Industrial-type programmable controllers were used for plant control and monitoring, computers with CAMAC front-end for data acquisition and timing. The shutdown to rebuild the machine power supply and to modify the magnetic structure offers the opportunity to update part of the ageing system to state-of-the-art technology. The concepts and the criteria for the updating of the system are reported and discussed in the paper. First of all, the system will fully exploit the multi-platform approach of the MDSPlus data acquisition package, which allows the use of distributed processors to handle data acquisition locally. CompactPCI has been selected as the hardware standard, due to its high performance, perspectives and low cost. A new timing system is also under development. This is engineered in CompactPCI format and is fully compatible with the existing CAMAC-based timing system. The control and monitoring system will rely, as far as possible, on hardware and software standards established in industrial automation, such as field-buses at cell automation level and industrial Ethernet at factory automation level.