What function does the "analog input" module perform in a PLC?

The function of the "analog input" module in a PLC is to convert analog signals into digital data. This process is crucial because PLCs primarily operate on digital signals for processing, calculations, and control. In many industrial settings, sensors and other devices provide data in the form of analog signals, such as voltage or current levels. The analog input module takes these continuous signals and samples them to produce discrete digital values that the PLC can understand and manipulate.

This conversion enables the PLC to effectively monitor variables like temperature, pressure, flow rates, and other critical process parameters that are vital for automation and control tasks. By transforming analog data into a format that the PLC can work with, the analog input module plays a critical role in bridging the gap between the physical world and the digital control environment of the PLC.