Profinet Redundancy

PLCnext Technology controllers enable redundant solutions by supporting two levels of Profinet redundancy:

Profinet Media Redundancy, namely the Media Redundancy Protocol (MRP) which is built up by redundant signal paths in the network (MRP ring).
Profinet System Redundancy (SR) which is built up by redundant Profinet controllers.

The topics contained in this help chapter give a short overview on these Profinet redundancy levels and explain how to setup your application project in PLCnext Engineer accordingly.

Further Info
For information on the topic of Profinet, see the Profinet website.

System Redundancy is independent from the net topology and media redundancy is independent from System Redundancy. Therefore, both redundancy levels can be combined or used independently of each other to ensure system availability.
In a higher expansion stage, for example, two controllers could be implemented (thus providing System Redundancy), and additionally, two MRP domains (each of which provides media redundancy).

Note
If a redundant system implements both, media redundancy and SR, the recovery time for the MRP ring must be kept small enough to ensure that the network switchover (to the backup MRP ring) is possible before the SR switchover (to the backup controller) occurs.
In such a system, the worst case maximum recovery time of the entire system would be the sum of the MRP recovery times plus the SR recovery time.

Example: Combination of MRP and SR S2