可编程控制器的高速输入口的应用

Application of High Speed Input of Programmable Logical Controller (PLC)

在设计用可编程控制器(PLC)控制的系统中,一般模拟量要通过专用的模拟模块来输入系统,即使整个系统只有一个模拟量,也要配置一个多通道的模拟模块,从而大大增加了系统的成本。为降低造价,可将模拟量经过压频(V/F)转换变成脉冲信号,输入PLC的高速输入口,再利用PLC的高速处理指令来实现模拟信号的数据采集,完成系统的控制。不用模拟模块也可采样到模拟信号,节省了造价较高的模拟模块。

When a system controlled by programmable logical controller (PLC) is designed,the input of analog signal is generally realized using analog module. Even if there is only one analog input signal for the whole system, an analog module with many channels has to be configured. Therefore, the cost of the system is significantly increased. To lower the cost of the system, the analog signal can be converted into pulse signal by V/F converter, and connected with the high speed input of PLC. Then the analog signal can be gathered using the high speed instruction of PLC, thus completing the control of the system. The analog signal can be gathered without the analog module, therefore, the cost of analog module can be saved.