Advantech eki-7656c, User Manual, Page: 33 / 114

2.8 Coupling Ring Application
As the illustration shown below, users can use the X-Ring groups to form a coupling
ring for redundant backup. It can ensure the transmissions between X-Ring groups not
to fail. The following figure is a sample of coupling ring application.
Note The Ethernet switches with firmware version before v3.0 use the X-Ring
function that has the limitations as follows. However, the ones with
firmware version after v3.0 (included) use the X-Ring Pro function that
gets rid of the limitations.
1. To ensure the coupling ring to work normally, the connection between
control ports of each X-ring group, as the figure illustrated above,
should always be active.
2. The switches to be configured as members of the Coupling Ring group
cannot be the X-Ring Master device of their X-ring group.
3. As the figure illustrated above, Coupling Ring only supports two X-ring
groups.
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