Flexibility, timeliness and efficiency in fieldbus systems: the DISCO project

The requirement for flexible operation is becoming increasingly important in many distributed computer controlled systems, in order to cope with dynamic operational changes in a resource efficient way. This requirement naturally extends to the low level of such systems where, typically, field equipment such as sensors, actuators and controllers, are interconnected by a fieldbus communication system. The paper presents the DISCO project (DIStributed embeddable systems for COntrol applications) that started in September 2000, in the University of Aveiro, aiming at exploring specification, architectural and management issues in flexible distributed computer control systems for embedded applications. The project addresses the issues of control requirements definition in a QoS perspective, flexible scheduling of both network traffic as well as nodes' computing load, and global system management techniques. The paper shows the results obtained so far as well as the status of the current work in the scope of the DISCO project.