Glossary · Automation fundamentals, platforms and components
Control level
Also known as: Control layer
German: Steuerungsebene
In the automation pyramid, the control level is the layer of controllers, such as PLCs, motion controllers and DCS controllers, that read field signals and execute the control logic in real time. It corresponds roughly to level 1 and parts of level 2 of ISA-95.
- Automation components
In one sentence
The control level is the layer of PLCs and other controllers that read field signals and run the control logic in real time.
Example
At the control level, the line PLC reads the light barriers at the field level and commands the conveyor drives.
How it applies
- Engineering: The control level has strict timing requirements; cycle times from milliseconds to tens of milliseconds are typical. Deterministic networks connect it to the field level.
- Security: Controllers are high-value targets, so the control level is usually its own security zone with restricted access.
- Documentation: System descriptions should list the controllers, their tasks, firmware versions and connections to the levels above and below.
- Maintenance: Controller replacement and firmware updates at the control level require backups of the project and a documented restore procedure.
Control level vs. field level
The Field level contains sensors, actuators and I/O. The control level contains the devices that process those signals and decide. With decentralized I/O and smart devices, the boundary is blurred, but the functional split remains useful.