VIPA System 200V IM Series, Manual

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Manual VIPA System 200V
Chapter 8 Ethernet coupler
HB97E - IM - Rev. 06/29 8-3
Basics
Originally, Ethernet has been developed from DEC, Intel and Xerox (as DIX
standard) for the data transfer between office devices. Nowadays it
normally means the specification
IEEE 802.3 CSMA/CD
, first published in
1985. Due to the worldwide deployment and the high lot sizes, this
technology is commonly available and reasonably priced. This allows the
easy link-up to existing networks.
Ethernet transports Ethernet packages from one sender to one ore more
receivers. This transfer happens without acknowledgement and without
repetition of lost packages. For a secure data transfer, protocols like
TCP/IP are used that are accompanying Ethernet.
In the early days of networking the Triaxial- (yellow cable) or thin Ethernet
cable (Cheapernet) was used as communication medium. This has been
superseded by the twisted pair network cable due to its immunity to
interference. The IM 253NET Ethernet coupler has a twisted-pair
connector.
Where the coaxial Ethernet networks are based on a bus topology the
twisted pair network is based on a point-to-point scheme.
The network that may be established by means of this cable has a star
topology. Every station is connected to the hub/switch by means of a
separate cable. The hub/switch provides the interface to the Ethernet.
The hub is the central element that is required to implement a twisted pair
Ethernet network. It is the job of the hub to regenerate and to amplify the
signals in both directions. At the same time it must have the facility to
detect and process segment wide collisions and to relay this information.
The hub is not accessible by means of a separate network address since it
is not visible to the stations on the network. A hub has provisions to
interface with Ethernet or another hub.
A switch also is a central element for implementing a twisted pair Ethernet
network. Several station res. hubs are connected together via a switch.
These then may communicate with each other via the switch without
causing network load. An intelligent hardware analyses the incoming
telegrams for every port of the switch and passes them collision free on to
the destination stations at the switch. A switch optimizes the band width of
every connected segment of a network. Switches allow changing exclusive
connections between the connected segment of a network.
Ethernet
Twisted Pair
Hub
Switch