Embedded EPICS based beam loss monitor system of HLS-II storage ring

A new beam loss monitor system based on embedded EPICS is developed for the top-off upgrade of HLS-Ⅱ, to monitor the position and value of beam loss of storage ring. The electron shower signals are obtained by the double PIN photodiode detectors around the storage ring, then acquired by the new BLM processors, where the beam loss signals are analysed and distributed to the accelerator control network, by embedded EPICS on embedded Linux system of the BLM processors, and the beam loss data could be obtained in the central control room. The new BLM system could actuate the self-checking function of the double PIN photodiode detectors, eliminate hidden malfunction of the detectors, and improve stability and reliability of the whole system. Preliminary operation shows that the new BLM system can meet the needs of the top-off upgrade of HLS-Ⅱ.