In PLC programming, what best describes an input module?

The best description of an input module in PLC programming is that it converts input signals into a format usable by the PLC. Input modules are designed to read various types of input signals from field devices, such as sensors and switches. These signals can be analog or digital, and the input module processes them, ensuring they are in a format that the PLC's processor can understand and work with. This conversion is crucial for the PLC to make decisions based on real-world data, allowing it to execute control logic effectively.

Understanding the role of an input module is essential, as it serves as the bridge between physical signals and the PLC’s internal logic. Without proper conversion by the input module, the PLC wouldn’t receive accurate data, thus impairing its functionality and impacting overall system performance.