Architectural design patterns for logic control of manufacturing systems: The generalized device

In all automated manufacturing systems the design of the control system plays a key role for the achievement of the targeted performance. A valuable support is provided by industrial technologies vendors in terms of computational platforms, smart I/O devices, networking infrastructures, integrated development and run-time environments. What is still lacking is a reference framework comprising a comprehensive set of highly reusable logic control components that, focusing on cross-cutting functionalities characterizing the automation domain, may help the designers in the process of modeling and structuring their applications according to the specific needs. As a first step in this direction, the paper introduces a set of new components that abstractly model the behavior of manifold field devices commonly used within automated manufacturing systems, regardless their nature, intrinsic features and specific functional purposes. These components, called generalized devices, are basic logic controllers/diagnosers, which play, in our architectural multilayer organization of the overall control logic, the fundamental role of keeping cleanly distinct higher-level control policies from low-level mechanisms dealing with actuators and sensors.