Lim, E.H. Chung, Y.S. Kim, E.-S. Kim, G.D. Kwon, J.W. Woo, H.J. JACoW Publishing Geneva, Switzerland 2673-5350 978-3-95450-230-1 10.18429/JACoW-IBIC2021-WEPP35 English 449-451 controls EPICS diagnostics operation status Contribution to a conference proceedings 2021 2021-10 https://doi.org/10.18429/JACoW-IBIC2021-WEPP35 https://jacow.org/ibic2021/papers/wepp35.pdf RAON has various diagnostic devices for measuring beam characteristics, such as Faraday Cup, Wire Scanner, and Beam Loss Monitor, etc. Each device is driven by PLC system and acquires current data with a DAQ based uTCA system. All the parameters are controlled by EPICS as process variables (PV) and monitored on GUI of CS-Studio. PVs of PLC and DAQ were named according to the RAON naming convention. Epics sequences are written in finite state machine code to work diagnostic device sequentially. Below we show the working principle of the epics based diagnostics devices control system and measurement results.