Technical information

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Topologies
Technical information
Ethernet network
Infrastructure
Different network topologies
Star topology
In a star topology, all devices and Data Terminal Equipment (DTE) are connected
though an intermediate device.
Ethernet star
In an Ethernet star the intermediate device may be a switch. The star is the most
commonly used topology in corporate networks and is currently adopted in almost
every automation application. As mentioned previously, for industrial Ethernet
applications the use of full duplex switches as the central device rather than hubs is
highly recommended.
Deploying star topologies with ConneXium
Star topologies can be implemented with any of the switches in the ConneXium offer.
Bus topology
The bus is one of the most common topologies in traditional industrial automation
networks. A single trunk cable connects all devices on the network usually via
passive or active T-connectors, or directly chained (daisy chain). Devices can
usually be installed anywhere along the bus.
Ethernet bus
An Ethernet bus can be deployed by interconnecting switches in line and
considering every one of them as the connection for a drop device. An unlimited
number of switches can be interconnected to achieve this purpose.
Deploying bus topologies with ConneXium
Bus topologies can be implemented with any of the switches in the ConneXium offer.
Switches with 1 or 2 ber optic ports are particularly suitable for this purpose:
b Switches with 2 ber optic ports can be used to connect in-line devices.
b Switches with 1 ber optic port can be used to connect end-of-line devices.
Daisy chain topology
Daisy chain - along the bus - is the other most common topology in traditional
industrial automation networks. Cable segments interconnect multiple devices,
being the devices “part” of the network cable.
Ethernet daisy chain
Daisy chain is currently not a particularly common Ethernet topology, but it is likely to
rise in popularity as more devices become available.
Ethernet daisy chain devices have:
b 2 Ethernet ports and
b 1 embedded switch.
Schneider Electric is launching Industrial Ethernet devices on the industrial market
for connection in daisy chain architectures.
Deploying daisy chain topologies
No switches are required for daisy chain topologies. All devices have an embedded
switch.
Dual port Ethernet at device level is an absolute integral component for daisy chain
topologies.
One port on the device connects to one port on each of the two neighboring devices.
These neighboring connections make up the daisy chain.
Ethernet switches can be employed in a daisy chain topology when multiple scan
chains are in use by the controlling device. It is expected that the Ethernet switch will
be located near the controlling device with the different scan chains emanating from
the switch.
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