What type of signals can a PID controller output?

A PID (Proportional-Integral-Derivative) controller commonly outputs analog signals. This is because PID controllers are designed to continuously adjust a control variable based on the measured error, which is the difference between a desired setpoint and a measured process variable. The output is typically a variable that can take on a range of values continuously, rather than being limited to specific increments or states.

Analog signals allow the PID controller to provide precise control by modulating the output in relation to the error in real time. For instance, the output might control a valve's position, a motor's speed, or other elements in a control system, ensuring smooth and responsive adjustments.

While digital and discrete signals are also used in various control systems, they are not the primary output of most PID controllers. Digital signals would represent output states in binary terms, which is less suitable for the gradual adjustments that a PID controller aims to achieve.