| Summary: | 碩士 === 大同工學院 === 資訊工程研究所 === 81 === This paper proposes a token-based Ethernet for CIM networ-
king. The proposed design is based on practical considerations
for applications in factory automation. The communication sys-
tems in factory are generally hierachical, linking low-level
devices to high-level master stations. The network hierachy is
studied to justify the role of the proposed network in modern
manufacturing environments. To overcome the unpredictable del-
ay time inherent to Ethernet, an additional function of token
control and management is implemented in the second layer of
the Ethernet network architecture. Ordered transmission is th-
en enforced to guarantee deterministic time-delays which are
basic requirement for real-time computer networks. Performance
of the proposed network is evaluated using a simulation tool
called SMPL. The results show that the token-based Ethernet w-
ill perform better under heavy system load. When the system l-
oad is low, the network will decrease its throughput owing to
the time-overhead of token-passing; however, the real-time re-
sponse property is still preserved. This property has made the
proposed network a feasible solution for CIM networking. Fina-
lly, we make some practical experiments to observe proposed n-
etwork the usage by using Ethernet Packet Driver, NetBIOS, and
Socket. Future perspective of this research is also disscused.
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