On different priority schemes for the message scheduling in Networked Control Systems

The message scheduling is an essential mechanism in the context of networked control systems (NCS). It strongly influences the stability of the closed loop distributed control applications. The goal of this paper is to present a study of different priority schemes which can be used for the message scheduling of a process control application implemented through a network (the network CAN will be considered). Two great schemes will be presented: static priority, hybrid priority including a dynamic part and a static part. The dynamic part is based on the dynamic performance of the controlled application. Considering the hybrid priority scheme, several types will be considered for the dynamic part: dynamic part alone, dynamic part and a static time strategy, dynamically controlled time strategy. The comparison of these schemes is done with respect to the stability of a process control application.