Media Redundancy Protocol (MRP)
7966_en_04
PHOENIX CONTACT
6-1
6
Media Redundancy Protocol (MRP)
6.1
General function
MRP stands for Media Redundancy Protocol. A ring topology ensures a switch-over time of
200 ms - 500 ms and is part of PROFINET standard IEC 61158.
A ring topology prevails. One switch is defined as the MRP manager, the rest are defined as
MRP clients. The MRP manager opens the port logically, i.e., the ring is only logically
interrupted (physically, the ring is still present). The data is transmitted over the network.
The MRP manager constantly sends test telegrams, known as watchdogs, via the logically
closed port. In the event of an error in the network, this is detected by the MRP manager and
the watchdog path is switched as a data cable.
If the error has been removed, this will also be detected by the MRP manager. The
watchdog path is automatically switched back and used again for test telegrams.
MRP manager
For licensing reasons, the switch that is configured as the MRP manager in the ring must
have a license key (FL MEM PLUG/MRM, Order No. 2891275).
You will require one license key for each MRP manager (for the configuration of the MRP
manager, see 6.3 “Configuration of MRP”).
Please note that MRP is disabled by default upon delivery.
