为了保证安全级分布式控制系统(DCS)对现场模拟信号采集的安全性和可靠性，需要在DCS模拟量采集的前端安装相应的隔离分配装置.采用电容充放电进行模拟量隔离，用定时器和逻辑门电路产生开关的控制时序信号.通过调整电容充放电时间，控制采样和保持的时序，配合光电开关实现对模拟信号的隔离，隔离后的模拟量信号经过电压电流转换后输出.经过对时序的控制器件参数的选择和匹配，在不校准的条件下，装置精度可达到0.05%，温度漂移低于2×10-5/℃，电气隔离度达到 1500Vp @1min＜5mA (Vp为峰值电压)，具有很好的电气特性和广泛的应用场景.

To ensure the safety and reliability of the safety level distributed control system (DCS) for live analog signal acquisition, it is necessary to place an isolation distribution device on the front end of the analog acquisition of the DCS. Capacitor charge-discharge was used for analog isolation, and timer and logic gate circuit were used to generate switching control timing signal. The function of isolating the analog signal by using the photoelectric switch, adjusting the charge-discharge time of the capacitor and controlling the timing of the sampling and holding. The isolated voltage signal was converted into a current signal output through the circuit. Through the selection and matching of the parameters of the timing control device, the device has good electrical characteristics and a wide range of application scenarios. Under the condition of uncalibration, the accuracy can reach 0.05%, the temperature drift is less than 2×10-5/℃, and the electrical isolation reaches 1500Vp@1min<5mA (Vp is the peak voltage).