Which component's primary function is to collect data and compare measurements to determine a control action?

Which component's primary function is to collect data and compare measurements to determine a control action?

• A. Open loops
• B. Controllers
• C. Input devices
• D. Thermostats

Answer: (B)

In a closed-loop system, the controller is the part that turns sensor data into a control action by comparing the measured value to the target and calculating the required response. It receives data from input devices (sensors), computes the error between what is and what should be, and outputs a control signal to the actuator to correct the process. This use of feedback—measuring, comparing to the setpoint, and deciding how to respond—is what defines the controller’s role. For example, a thermostat reads room temperature, compares it to the desired temperature, and switches the heater on or off to bring the temperature to the setpoint. Input devices simply gather data, and open-loop systems don’t use this feedback to adjust actions.

In a closed-loop system, the controller is the part that turns sensor data into a control action by comparing the measured value to the target and calculating the required response. It receives data from input devices (sensors), computes the error between what is and what should be, and outputs a control signal to the actuator to correct the process. This use of feedback—measuring, comparing to the setpoint, and deciding how to respond—is what defines the controller’s role. For example, a thermostat reads room temperature, compares it to the desired temperature, and switches the heater on or off to bring the temperature to the setpoint. Input devices simply gather data, and open-loop systems don’t use this feedback to adjust actions.