Profinet Media Redundancy - Siemens SINAMICS S120 Series Function Manual

5.8

PROFINET media redundancy

To increase the availability of PROFINET, you can create a ring topology. If the ring is
interrupted at one point, the data paths between the devices are automatically reconfigured.
Following reconfiguration, the devices can once again be accessed in the resulting new
topology.
To create a ring topology with media redundancy, route the two ends of a line-type
PROFINET topology to a switch which serves as redundancy manager (e.g. a suitable
SCALANCE switch). Closing the linear bus topology is realized using two ports (ring ports) of
the SCALANCE redundancy manager, which monitors the data telegrams in the PROFINET
ring. All other connected PROFINET nodes are redundancy clients.
The Media Redundancy Protocol (MRP) is the standard procedure for media redundancy.
Using this procedure, a maximum of 50 devices can participate in each ring. In the case of
an interrupted cable, data transfer is only briefly interrupted as the system switches over to
the redundant data path: This is the reason that the switchover is not bumpless (200 ms).
If a brief interruption is not permitted, then you have the following options
● Correspondingly set the failure monitoring time in the hardware configuration to more
than 200 ms.
or
● Set the data transfer to IRT High Performance.
The uninterruptible MRRT is automatically set. A SIMOTION controller (or another suitable
controller) is required in this case.
The two integrated PROFINET IO interfaces of the Control Units CU320-2 PN and CU310-2
PN can be configured as redundancy clients.
From a CBE20, only the first two ports are capable of establishing a ring topology. Routing
between the integrated PROFINET IO interfaces and a CBE20 is not possible.
Communication
Function Manual, 12/2018, 6SL3097-5BD00-0BP0
Communication via PROFINET IO
5.8 PROFINET media redundancy
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