Current Status of Control System for PLS 2-GeV Linac

I. S. Ko
Pohang Accelerator Laboratory


A distributed control system has been developed and successfully operated for the PLS 2-GeV linac. The system has three layers of hierarchy: operator interface computer, supervisory control computer (SCC) for data processing, and device interface computer (DIC) for distributed data acquisition. The operator interface is based on UNIX system with graphic-based development system named RTWorks. The SCC consists of three subsystems: modulators and klystrons, magnet power supplies, and beam diagnostics. DICs attached to individual devices are placed around the 200 m-long linac building. There are altogether 22 VME CPUs and various I/Os in SCC and DIC levels. The realtime operating system is OS-9. During the preventive maintenance period of this year, several upgrades have taken place. For example, beam loss monitors and beam current monitors are added in the beam diagnostic station. We use fast sample and hold circuits to read 2-ns long pulse signals from the beam current monitors. Other upgrades and improvements will be reported in this paper.