Using distributed intelligence to control the vacuum system of a very large accelerator

The control system for the LEP machine is based on the concept of distributed intelligence. Hence the controls for the Vacuum System have to follow the same approach. There are a number of benefits available from having disctributed computing power, among them the possibility of having powerful control devices made available to the vacuum operators on the site where they work rather than in a central control room. The paper outlines the advantages of having so-called intelligent equipment controllers for every item installed, which makes it possible to control them via a local area network, using standardised messages. This local area network, though completely transparent to the main control room, allows complete independence at the level of a vacuuum sector when the genral control system is not available. This contribution also describes in some details the light pen driven mobile consoles which were used during the commissioning of the LEP Vacuum System, providing the operators with a global overview of the equipment they had to control from anywhere in the LEP tunnel.