Siemens SIMATIC ET 200AL, System Manual

Page: 1753 / 2255

Functions
5.4 Media redundancy (ring topologies)
PROFINET with STEP 7
188
Function Manual, 05/2021, A5E03444486-AL
5.4.5 MRP interconnection
Definition
The process MRP interconnection is an enhancement of MRP and allows the redundant
coupling of two or more rings with MRP in PROFINET networks. MRP interconnection is - like
MRP - specified in the standard IEC 62439-2 (Edition 3).
Advantages
MRP interconnection allows the monitoring of larger topologies with ring redundancy. With
MRP interconnection, you are not limited to the maximum number of 50 devices in a ring
when setting up redundant network topologies. For information on the quantity structure of
MRP Interconnection, refer to the SCALANCE XM-400/XR-500 Web Based Management (WBM)
( https://support.industry.siemens.com/cs/ww/en/view/109760840 ) configuration manual.
Requirements
• The media redundancy procedure MRP is used in the participating rings.
• Each ring has its own MRP domain with an MRP manager and MRP clients.
• As MRP managers in the rings, the PROFINET devices support MRP interconnection (see
technical specifications of the devices).
S7-1500 CPUs as of firmware version V2.9 support MRP interconnection.
• If you use PROFINET devices with more than 2 ports as MRP clients in the ring, then MRP
interconnection is binding for these devices. For a device without MRP interconnection,
telegrams leave the ring. This results in an additional load on the network.
• If you use PROFINET devices with only 2 ports in the ring as MRP clients, then MRP
interconnection is recommended for all devices in the ring.
4 devices for MRP interconnection connections
2 MRP-interconnection connections provide redundant coupling between 2 MRP rings. Four
devices are required for the 2 connections:
•
A Media Redundancy Interconnection Manager (MIM)
• 3 media-redundancy interconnection clients (MIC):
– Primary MIC
– Primary Coupled MIC
– Secondary Coupled MIC
Since each of the four devices is part of an MRP ring, each device also assumes a media
redundancy role.
Each of the 4 devices can take over the MRP manager role or MRP client role.