Glossary · Distributed automation and IEC 61499
Application model
Also known as: IEC 61499 application, Application (IEC 61499)
German: Anwendungsmodell
In IEC 61499, the application model describes an application as a network of function block instances connected by event and data connections, independent of the devices and resources on which it will eventually run.
- IEC 61499
- Standards
In one sentence
The IEC 61499 application model describes an application as a network of connected function blocks, independent of hardware.
Example
A bottle-sorting application is modeled as a network of sensor, decision and actuator function blocks before anyone decides which controllers will run it.
How it applies
- Engineering: The application model is the hardware-independent core of an IEC 61499 design. It can be structured with subapplications and reused across systems. Hardware is added later through the system configuration and Application mapping.
- Systems engineering: The approach mirrors model-based systems engineering, where a functional architecture is allocated to physical components. See System model.
- Change management: Because applications are hardware-independent, the same application version can be deployed to different hardware configurations. Both the application version and the mapping define the deployed system.
- Documentation: Application diagrams are useful as functional documentation. Add a short description of each subapplication's purpose and its interfaces, so that readers who do not know the tool can follow the design.
Application model vs. device model
The application model describes the functions. The Device model (IEC 61499) describes the hardware that executes them, with its resources and interfaces.