Improvement of photon factory advanced ring control system

As a part of the Photon Factory Advanced Ring (PF-AR) upgrading project, the control system is upgraded. Considering the importance to realize the seamless operation between PF-AR, injector linac and KEKB, we decided to adopt EPICS as a basis of the control system. The old control system of the PF-AR was based on the HIDIC mini computer system and the CAMAC was used as a field-bus. In order to minimize the cost and the work of renewal, we didn´t change the device interface layer below CAMAC. A total of 13 EPICS Input/Output controllers (IOCs) are used to replace HIDIC mini computers, and we use the VME modules such as CAMAC crate controller, GPIB interface and the timing synchronization module. The ARCNET driver modules are also used mainly for the control of magnet power supplies. For the archiving of accelerator parameters, we use Channel Archiver, which is one of the EPICS extensions. We have also renewed the accelerator safety control system using the PLC.