Image Processing Reference
In-Depth Information
26
Hybrid Wired/Wireless Real-Time
Industrial Networks
. Introduction .........................................
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. RelevantIndustrialNetworks ........................
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Profibus DP and Profinet IO
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DeviceNet and EtherNet/IP
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IEEE .
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IEEE ..
. ImplementationofHybridNetworks.................
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Interconnections at the Physical Layer
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Interconnections at
the Data-Link Layer
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Interconnections at Higher Protocol
Layers
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Wireless Extensions of Industrial Networks
. IEEE.-BasedExtensions:Fieldbuses ............
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Extensions of Profibus DP
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Extensions of DeviceNet
. IEEE.-BasedExtensions:RTENetworks........
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Extensions of Profinet IO
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Extensions of EtherNet/IP
. IEEE..-BasedExtensions......................
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Extensions of Fieldbuses
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Extensions of RTE Networks
. Conclusions..........................................
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References .................................................
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Gianluca Cena
National Research Council
Adriano Valenzano
National Research Council
Stefano Vitturi
National Research Council
26.1 Introduction
The past two decades have witnessed the ever-increasing adoption of advanced digital communi-
cation technologies in industrial automation and manufacturing environments. Field networks (also
knownwiththeterm“ieldbuses”)[]arecertainlythemostpopularsolutioninthosescenarios.Since
a long time, they are being used at the lowest levels of factory automation systems (shop-floor) that
are often characterized by tight timing requirements. On the other hand, Ethernet networks, which
were traditionally adopted as factory backbones to handle information flows between different areas
of the plant, are now deemed suitable to support also the communication needs of distributed control
applications down to the field level. This is mostly due to the noticeable enhancements concerning
performance and determinism brought to this kind of networks over the years, which led, in the
recent past, to the development of industrial Ethernet solutions purposely designed to support real-
time communications []. It is worth noting that, in several cases, variants of such protocols have
been defined that are able to support isochronous communications as well, like those required in
demanding the motion control systems.
The above-mentioned scenario, however, is quickly evolving. Other kinds of communication
technologies, i.e., wireless networks, are now very popular and related devices are widely available
off-the-shelf at reasonable prices. Wireless communications are becoming more and more pervasive
