Name: | Description: | Size: | Format: | |
---|---|---|---|---|
181.09 KB | Adobe PDF |
Advisor(s)
Abstract(s)
Fieldbus networks aim at the interconnection of field devices such as
sensors, actuators and small controllers. Therefore, they are an effective
technology upon which Distributed Computer Controlled Systems (DCCS) can
be built. DCCS impose strict timeliness requirements to the communication
network. In essence, by timeliness requirements we mean that traffic must be
sent and received within a bounded interval, otherwise a timing fault is said to
occur. P-NET is a multi-master fieldbus standard based on a virtual token
passing scheme. In P-NET each master is allowed to transmit only one message
per token visit, which means that in the worst-case the communication response
time could be derived considering that the token is fully utilised by all stations.
However, such analysis can be proved to be quite pessimistic. In this paper we
propose a more sophisticated P-NET timing analysis model, which considers
the actual token utilisation by different masters. The major contribution of this
model is to provide a less pessimistic, and thus more accurate, analysis for the
evaluation of the worst-case communication response time in P-NET fieldbus
networks.
Description
Keywords
Citation
Publisher
Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto
Universidade do Porto
University of York
Universidade do Porto
University of York