As well as sensors and actuators, controllers are a central element of automation technology. The term control technology or industrial control technology stands for devices that control, regulate, monitor, collect data, communicate, and diagnose. In a narrower sense, we understand "control" in automation technology as the influencing of a material or energy flow by a closed loop system in which multiple signals are processed. In turn, the result influences the closed loop system, and the input value influences the controlled output value.