A control loop—often referred to in German as a “Regelkreis”—describes the automatic control of a physical process through feedback. In industrial plants, the control loop plays a central role in maintaining defined process parameters such as temperature, pressure, or flow rate. Process controllers and process control systems ensure continuous real-time acquisition, evaluation, and adjustment of measured values.
How a control loop works
A control loop typically consists of four main components: a sensor, a controller, an actuator, and the process being controlled. The goal is to automatically correct deviations from the setpoint to ensure stable and reproducible process conditions.
As an example, a typical control loop proceeds as follows:
- Measurement: A sensor records the current actual value (e.g., temperature in the oven)
- Control: The process controller compares the actual and setpoint values
- Control command: If there is a deviation, the actuator (e.g., heating power) is adjusted
- Feedback: The effect is measured again—the control loop closes
Application in heat treatment
In thermal processes such as hardening, annealing, or sintering, the control loop is crucial for uniform heat distribution and process reliability. Complex industrial furnaces often have multiple simultaneous control loops (e.g., for different zones) that must operate in sync. Demig relies on high-resolution sensors, precise process controllers, and intelligent signal processing to reliably meet these requirements.
Integration into modern process control systems
A single Controlloop provides stable results only locally. Only by connecting to a higher-level process control system can a comprehensive overview of all control loops, batches, and plant statuses be achieved. The advantages of this integration include:
- Centralized Parameter Configuration and Monitoring
- Visualization of all control loops with status display
- Alarm and trend functions for early fault detection
With solutions such as prosys/2, Demig ensures that individual Controlloops do not operate in isolation, but rather as part of a holistically controllable production network.
Conclusion
The Controlloop is the technical backbone of any automated process control system. In combination with high-performance process controllers and a networked process control system, this creates a stable, efficient, and documented production process—indispensable for meeting the highest quality requirements in heat treatment. Demig offers well-designed, scalable solutions for plants of all sizes.