Abstract: It introduces the principle of the Liquid Nitrogen Cooled Double Crystal Monochromator（LNCDCM） in SSRF（Shanghai Synchrotron Radiation Facility）. It describes the functions of controlling the step motors of the DCM, scanning the energy, acquiring the signals of detectors, switching between two crystals, compensating the height and saving the parameters of the positions of the DCM with EPICS. The experimental results show that the DCMs provide satisfied synchrotron radiation light and the motion control system achieves and excels the design goals.

Key words: Experimental Physics and Industrial Control System（EPICS）, Shanghai Synchrotron Radiation Facility（SSRF）, Liquid Nitrogen Cooled Double Crystal Monochromato（LNCDCM）, motion control

摘要： 介绍了上海光源液氮冷却单色器的工作原理，描述了在EPICS环境下实现单色器步进电机控制、能量扫描和探测器信号实时获取、晶体切换和高度补偿以及单色器姿态参数保存等功能。实验结果表明，单色器能够提供满足实验要求的同步辐射光，运动控制系统的各项指标达到或优于设计目标。

关键词: 实验物理和工业控制系统（EPICS）, 上海光源, 液氮冷却单色器, 运动控制