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PROFIBUS Power Hub Segment Coupler 3 (SK3)
Operation
In the case of redundant coupling, rebooting the gateway results in a redundancy
switchover. After that, repeat these steps to update the firmware for the second gateway as
well.
6.4
Redundant Operation
Redundancy Behavior
During redundant operation, the gateway simulates PA slaves for the DP bus. From the point of
view of the DP bus, redundancy switchover has no visible effect on the master. All slaves
remain in the cycle. This transparent redundancy (TR) differs from normal flying redundancy
(FR) behavior, which allows slaves to drop out of the cycle for a defined time.
The HD2-GTR-4PA supports all masters that work on the flying redundancy principle, as well
as all non-redundant masters.
The built-in slave automatically detects whether the DP master is using a redundancy concept.
If the DP master is working according to the flying redundancy concept, the gateway
automatically adjusts itself accordingly without any manual setting required.
With transparent redundancy, exchange of user data remains intact. In the worst case, only
non-critical acyclic data exchange drops out.
System Environment for Redundant Operation
In redundant operation, both built-in slaves (primary and secondary gateway) should be in
cyclic data exchange. Assigning bus addresses to both gateways makes it easy to monitor both
built-in slaves with the master which detects the failure of 1 of the 2 built-in slaves and reports
the relevant slave address.
The PROFIBUS Power Hub provides redundant coupling of PA segments in the following
system environments:
Combined with a non-redundant master
■
In a flying redundancy system
■
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