plc-basedBNC²³⁶²¹³⁺¹ 例句 Owing to the limited frequency of the internal high-speed counter of PLC, the peripheral unit of PLC is used for PLC-based frequency measurement of hydraulic turbine governors. 基于可编程序控制器 PLC的水轮机调速器，受 PLC内部高速计数器最高计数频率的限制，频率测量大多通过 PLC外部单元来实现。 cnki