UPGRADE OF THE SPRING-8 LINAC CONTROL BY RE-ENGINEERING THE VME SYSTEMS FOR MAXMIZING AVAILABILITY

Abstract

Control system re-engineering of a mission-critical working accelerator is a problem, but it is possible with well-defined procedures and methodology. We have finished an upgrade of control system of a 1GeV electron linac in SPring-8. The upgrade was divided into two phases, taking into consideration the availability of the linac. In the first phase, we mainly replaced software part with SPring-8 standard framework. In the second phase, we re- engineered the VME systems to maximize availability of the linac operation considering reliability, usability, expandability and flexibility. We newly developed an optically linked remote I/O system and intelligent motor control units. By adopting these systems, we could re- allocate the VME controllers away from known noise sources and also reduce the number of the controllers. All interface connector boxes were re-designed and replaced to achieve easy maintenance and expandability. We report the upgrade of the linac control system by focusing on the methodology with introducing the new remote I/O system and the motor control unit.