Siemens SCALANCE X-200 - Manual (Page 13)

Network Topologies
3.1 Network Topologies
Ring Topology
Figure 3-4 Ring Topology, Example with SCALANCE X204-2 and SCALANCE X-400 as
Redundancy Manager
To increase availability, optical or electrical bus topologies made up of SCALANCE X-200
switches with a SCALANCE X414-3E, OSM version 2, or ESM version 2 configured as a
redundancy manager can be closed to form a ring. The SCALANCE X-200 switches are first
connected over their ring ports to form a bus. The two ends of the bus are closed to form a
ring by a SCALANCE X414-3E or OSM / ESM operating in the redundancy manager mode.
In contrast to the ring ports of the SCALANCE X-200 switches, the ring ports of the
redundancy manager are disconnected from each other during problem-free network
operation.
The SCALANCE X414-3E or OSM / ESM operating in the redundancy manager mode
monitors the connected bus over its ring ports and switches the ring ports through if there is
an interruption on the connected bus; in other words, it restores a functioning bus over this
substitute path. Reconfiguration takes place within 0.3 s.
As soon as the problem has been eliminated, the original topology is restored; in other
words, the ring ports in the redundancy manager are once again disconnected from each
other.
Industrial Ethernet SCALANCE X-100 and SCALANCE X-200 Product Line
Commissioning Manual, 1,
3-3