Control of the J-PARC Slow Extraction Line Based on Embedded EPICS
A.Kiyomichi, H.Nakagawa, J.-I.Odagiri, K.O.Okamura, M.Tomizawa, N.Kamikubota, N.Yamamoto, R.Muto, S.Murasugi, Y.Shirakabe (KEK) M.Takagi* (Kanto Information Service (KIS), Accelerator Group)
The J-PARC Main Ring supplies high energy proton beams to the hadron experiment facility through the slow extraction line. It comprised of a series of septa, staring from a pair of electrostatic septa (ESS) followed by magnetic septa, and some of those septa are movable by using stepping motors to adjust their positions for a better optics. In order to control the power supplies of the septa and the stepping motors, an EPICS-based control is implemented based on a new type of Input / Output Controller (IOC), which runs Linux on a CPU module of FA-M3 Programmable Logic Controller (PLC). The CPU functions with normal I/O modules of FA-M3 on the PLC-bus. The most remarkable feature of the control system is that we replaced ladder programs with EPICS sequencer programs for the efficiency of the software development and ease of maintenance. And we found that the new type of IOCs had worked without any serious troubles during the beam commissioning period, from Run#21(Jan.2009) through Run22(Feb.2009). This paper describes the details of the new IOC and its experiences in J-PARC operation including long term stability.