CONTROL-SYSTEM OF PLS 2-GEV ELECTRON LINAC

A graphic-based realtime control system is developed and used for comm issioning and operation of the PLS 2-GeV electron linac. The system ha s three layers of hierarchy; operator interface computer, supervisory control computer (SCC) for data processing, and device interface compu ter (DIC) for distributed data acquisition. The operator interface is based on the UNIX system with a graphic-based development system named RTworks. The SCC consists of three subsystems; modulators, magnet pow er supplies, and beam diagnostics. DICs attached to individual devices are placed in the 200-m linac building. There are altogether 23 VME C PUs and various I/Os in both SCC and DIC levels. The realtime operatin g system is OS-9. The major role of DICs is to control and to monitor individual devices upon operator's requests. The SCC updates variable database from DICs and conveys commands from the operator to DICs. SCC s and DICs are connected through a local area network to form a client /server system. Low-cost workstations are used for the operator interf ace. In order to have quick manipulation and easy understanding we use intensive graphics for the control windows.