X20 system modules • X20 interface module communication • X20IF2181-2
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X20 system User's Manual 3.10
4.23.25.9 POWERLINK cable redundancy system
It is often indispensable to have redundant network cabling, especially in systems that handle technical processes.
The potential for danger, especially to the lines that run through the system, is disproportionately high in relation
to the need to keep communication active in all operating situations. This risk is effectively reduced with double
cabling that is routed separately.
The POWERLINK cable redundancy system is based on the principle of doubling the transfer routing as well as
providing continual and simultaneous monitoring. That means data is simultaneously fed into two cable lines using
a corresponding mechanism. The same mechanisms are used to receive these telegrams from the redundant
network.
Information:
•
Networks 1 and 2 must always have the same topology and run parallel from a logical stand-
point. In other words, the number and logical arrangement of the hubs must be the same in both
networks. It is also important that cable lengths between segments are the same in Network 1
and Network 2 (see 4.23.25.9.6 "Topology examples" on page 1872).
•
The double cabling used with POWERLINK cable redundancy makes it possible to manage one
or more errors on a network. These errors must occur simultaneously either only on network 1
or only on network 2. Errors occurring on both networks at the same time can cause stations
to fail.
The following modules are available for the POWERLINK cable redundancy system:
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Interface module X20IF2181-2
•
Link selector X20HB8884
•
X20BC8084 bus controller
Summary of Contents for X20 System
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