Which of the following best describes the function of a PLC power supply?

The function of a PLC power supply is crucial for the operation of the PLC system as a whole. It converts external electrical power, typically from an AC main supply, into a suitable DC voltage level that the PLC can use. This conversion ensures that all components within the PLC, including the CPU, input/output modules, and other connected devices, receive a stable and regulated power supply. A reliable power source allows for consistent operation of the PLC, enabling it to process inputs and execute logic without interruption.

Understanding the role of the power supply is vital because it serves as the backbone of the entire PLC system, supporting all its functionalities by providing the necessary energy for processing signals and controlling operations. Other options, such as increasing signal strength or relaying signals, do not accurately describe the primary function of the power supply and instead refer to different components and processes within a control system. Additionally, interfacing sensors with the CPU pertains more to signal processing and data communication rather than the conversion and regulation of electrical power.