上海光源储存环运行在恒流注入(top-up)模式下每10 min注入一次，注入引起的β振荡为测量工作点提供了有利条件。通过数字束流位置处理器采集储存环注入时的逐圈数据，对数据进行快速傅里叶变换计算获得工作点，以此搭建了刷新间隔为10 min的工作点在线监测系统。2014年上半年的运行结果表明，该系统能够有效检测工作点变化并评估加速器工作点可达到的最优性能。利用该系统能够及时发现加速器运行异常，并结合各设备运行状态可有效定位异常原因。

The storage ring at Shanghai Synchrotron Radiation Facility (SSRF) is operating at the top-up mode, which is injected every 10 minutes. The transverse betatron oscillation introduced during the injection can be used to calculate the tune of the machine. A real-time tune measurement system has been built where the Fast Fourier Transformation (FFT) of the turn-by-turn beam position data from digital BPM processors is calculated at injection rate. Long-term results of the first half of 2014 show that the system is capable of monitoring tune shift effectively, and can be used to evaluate the best tune performance of the storage ring. Meanwhile, the system can detect operation abnormality in time and locate the malfunction causes effectively after analyzing related systems. It is an effective tool for the operation and optimization of the machine.