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RSTI-EP PROFINET I/O Controller User Manual Section 6
GFK-2571R May 2021
Redundant Media 141
up. The PROFINET Controller disables all its external Ethernet ports until it has retrieved and
applied the Media Redundancy Protocol configuration from its non-volatile storage.
If a configuration containing a PROFINET Controller set up as a Media Redundancy Manager
is subsequently used to generate another configuration, using Generate Secondary
Hardware Configuration from the Current Configuration, for example, the PROFINET
Controller configuration in the copy is automatically defaulted to a Media Redundancy
Client.
6.5 Sequence for Enabling Media Redundancy
To avoid network loops occurring before the Media Redundancy configuration parameters
are stored, the network must first be set up with the ring broken at one point. Otherwise,
packets could continuously cycle on the network and use up significant network bandwidth.
The ring should not be closed until the Media Redundancy configuration parameters are
successfully stored to the Media Redundancy Manager and the Media Redundancy Manager
is operational.
If more than one Media Redundancy Manager is present on the same ring, each PROFINET
Controller that is configured as a Media Redundancy Manager will log a fault in its Local Log
and in the RX3i CPU’s I/O Fault Table. W hen the RX3i configuration is cleared, the Media
Redundancy configuration parameters (Media Redundancy Manager or Client) are kept
until a new setting is stored. If power is lost, the Media Redundancy configuration settings
are preserved.
Note:
When configuring a Media Redundancy Manager in an open ring, the module may
initially report the ring to be closed. This indication will immediately be followed by a ring
open event. This is expected behavior defined by the MRP specification.
6.6 Sequence for Replacing a Media Redundancy
Manager
If it is necessary to replace the PROFINET Controller that is serving as the Media Redundancy
Manager, the replacement module must be set up as a Media Redundancy Manager before
adding it to the ring. Alternatively, the ring must be opened before powering up the new
module and adding it to the network, as described above.
The following procedure can be used to replace a PNC001 module that is operating as Media
Redundancy Manager without disrupting the network.
1. Verify that the ring has no breaks in it, or that the only break involves the Media
Redundancy Manager itself. If the ring is already broken someplace else, the Media
Redundancy Manager must always remain operational or connectivity between the
remaining devices is not guaranteed.
2. Physically disconnect both ring’s network connections from the PNC001 module that
is serving as the Media Redundancy Manager.
3. Remove the disconnected PNC001 module from the RX3i rack.