Component-based Control Software design using IEC 61499 Adapter Interfaces

Control software components in the Cyber-Physical Systems domain use Function Blocks (FBs) to implement system logic, which manages interactions among hardware components (e.g., sensors and actuators) and other control software modules. FBs provide discrete input and output interfaces that support unidirectional data and event connections, which facilitate the integration of multiple subsystems to meet overall system requirements. However, this design based on discrete interfaces results in a high number of connection instances and lacks encapsulation. The complexity is further compounded by implicit one-to-many (fan-out) connections among subsystems, which can hinder both system understandability and maintainability. To address these challenges, we propose leveraging the adapter interface concept from IEC 61499. This approach replaces multiple discrete connections with a single bidirectional adapter connection that explicitly defines interaction requirements between components. Consequently, this reduces visual complexity and enhances system maintainability and testability.