Which component is commonly used to convert an analog signal into a digital signal in control systems?

The choice of an analog-to-digital converter (ADC) is appropriate because this component is specifically designed to transform continuous analog signals into discrete digital signals. In control systems, these signals often represent physical quantities such as temperature, pressure, or voltage, which need to be processed by digital devices such as microcontrollers or digital signal processors.

The process of conversion typically involves sampling the analog signal at a series of points in time and quantifying these values into a digital format that can be interpreted and manipulated by digital systems. This capability is crucial for modern control systems, which rely on digital processing techniques for tasks such as feedback control, data logging, and system monitoring.

Other components, while important in their own right, do not fulfill the specific function of converting analog signals to digital signals. For example, optical isolators are used for protecting circuits by electrically isolating different parts of the system, relays are used for switching applications, and PID controllers are algorithms used in control systems for maintaining a desired output, but they do not perform the signal conversion that an ADC does.