Architecture of the LEP2 cryogenics control system : Conception, status, and evaluation

Abstract Conception and realisation of the industrial process control system and application programs for the four new 12 kW/4.5K cryoplants, and the 192 superconducting accelerating cavities, were critical activities in the implementation of the cryogenic system for the LEP2 project at CERN. The main objectives like regulation quality, automatic restarts, centralised remote control, homogenisation of the logics for the cryoplants built by different suppliers are exposed as well as the current state of advancement. The modular distributed control system hardware is presented. The architecture of software using an object oriented programming method is described. A tentative evaluation is presented with a general view on work and costs, from which follow conclusions concerning future control systems for similar projects.