提出了一种应用于小型PLC(Programmable Logic Controller)的工作状态监视方法，即使用数码管增加简单可靠的人机界面，使工作人员可以直观的了解PLC内部程序状态，为小型PLC的运行、维护和检修提供便利。
The paper provides a method which can be applied to the surveillance and display of the working condition of the small PLC. Using Nixie Tube to add an efficient human-computer interface enables operating staff to know the internal condition of the PLC procedure directly. It will facilitate the operation, maintenance and reparation of PLC in small scale industries.
