引言仪表及控制系统的可靠性直接影响到现代化工业生产装置安全、稳定运行,系统的抗干扰能力是关系到整个系统可靠运行的关键。随着DCS、现场总线技术的应用,被控对象和被测信号往往分布在各个不同的地方,并且他们与控制站之间也有相当长的距离,因此,信号线和控制线均可能是长线。其次,现场往往有 Introduction The reliability of instruments and control systems directly affects the safe and stable operation of modern industrial equipment. The anti-interference ability of the system is the key to the reliable operation of the entire system. With the application of DCS and fieldbus technology, the controlled object and the signal under test are often distributed in different places, and there is also a long distance between them and the control station. Therefore, both the signal line and the control line may be long lines. Second, the scene is often there