Performance analysis and real time assessment of the prioritized tokenbus access method according to the manufacturing automation protocol (MAP)

The paper studies the performance of the prioritized tokenbus access mechanism and assesses its real time capability. It provides an in depth analysis of the access scheme and validates the obtained results by means of measurements. Only the first two layers (Phy and MAC) are considered in the authors´ performance investigation. It provides some rules on how the MAC-timers have to be set, in order to obtain a desired throughput characteristic of the three lower access classes, fulfilling certain real time constraints for messages belonging to the access class 6