Which component develops an error signal in automatic control?

The PID controller is responsible for developing an error signal in an automatic control system. This is achieved by continuously comparing the desired setpoint to the actual process variable. The difference between these two values is termed the error signal. The PID (Proportional-Integral-Derivative) controller processes this error signal to adjust the control output accordingly, striving to minimize the error over time.

This functionality is essential in maintaining the desired operation of a system by implementing corrective actions based on the error signal. The proportional term reacts to the present error, the integral term responds to the accumulation of past errors, and the derivative term predicts future errors. This comprehensive approach allows the PID controller to effectively manage system performance and stability.

In contrast, other options like the signal conditioner serve to prepare and modify signals for processing, the data logger primarily records and stores data for analysis, and the feedback loop is a mechanism used in control systems but does not specifically generate the error signal. Thus, the PID controller is the key component specifically tasked with developing that crucial error signal for automatic control.