Modeling distributed embedded applications on an interface file system

This paper presents a framework for generic modeling of distributed embedded applications. An application is decomposed into services and mapped on a set of distributed nodes, whereas each node hosts one or more services. Each service is described by four interfaces: a real-time input/output, a configuration and planning (CP), and a diagnostic and management (DM) interface. The overall application is described by a cluster configuration description that specifies the interaction of services within and across nodes. The application requirements, the service properties of a node, and the interaction of the services as well as the application mapping are described formally with XML descriptions. The XML format allows a language-neutral and extensible semantic description of interfaces supporting the implementation of context-aware tools for modeling, scheduling, monitoring, simulation, and validation. A central concept of the model is the interface file system (IFS) that acts as a distributed shared memory and transparently implements the interfaces to services from other nodes. In principle, the communication system that updates the data in the IFS data is not bound to a specific implementation as long as it fulfills the given timing requirements. The presented concepts are applied in a case study that uses the time-triggered fieldbus protocol TTP/A for the implementation of a small sensor fusion application