Profinet MRP: Ensuring Continuous Industrial Networking

Explore the power of Profinet MRP for industrial networks, ensuring continuous operation with its fast recovery and network resilience. A concise guide to boosting efficiency and reliability in automation systems.

In the realm of industrial automation, maintaining uninterrupted network communication is critical. Network resilience not only supports continuous operation but also safeguards against potential downtime and associated costs. This is where Profinet Media Redundancy Protocol (MRP) becomes a cornerstone technology, offering a solution designed to enhance network reliability and ensure seamless operation in industrial environments.

What is Profinet?

Before delving into MRP, it’s essential to understand Profinet. Profinet is an open industrial Ethernet standard for automation, providing comprehensive solutions for all areas of automation technology. It facilitates communication between numerous devices in an industrial network, including controllers, field devices, and human-machine interfaces. Profinet leverages standard Ethernet technology to meet the demanding requirements of industrial automation, such as real-time data exchange, flexibility, and high system availability.

Media Redundancy Protocol (MRP)

The Media Redundancy Protocol is a key feature within the Profinet standard aimed at achieving network redundancy. MRP is specifically designed to ensure that communication continues even if a single point of failure occurs in the network topology. This is achieved by creating a ring topology among the network devices, where each device is connected in a loop. To set up an MRP loop, all nodes in the ring must support MRP

How MRP Works

1. Ring Topology: At the core of MRP is a ring topology, where all devices are interconnected in a closed loop. One of the devices in the ring is designated as the Media Redundancy Master (MRM), while the others are Media Redundancy Clients (MRCs).

2. Normal Operation: Under normal conditions, the MRM sends out periodic test frames to monitor the integrity of the network. These frames circulate through the ring, passing through each MRC, and eventually return to the MRM. (Figure 1)

3. Detection of Failure: If the MRM detects a failure in the ring—such as a broken cable or a malfunctioning device—it promptly identifies the disruption in the test frame circulation.

4. Reconfiguration: Upon detecting a failure, the MRM reconfigures the network within milliseconds, ensuring that data continues to flow between all operational parts of the network. This is achieved by opening the ring at the point of the MRM, effectively transforming the ring topology into a line topology that bypasses the point of failure. (Figure 2)

5. Recovery: Once the failure is resolved and the network integrity is restored, the MRM automatically reverts the network back to its original ring topology, closing the loop and re-enabling the redundancy mechanism.

Profinet MRP

Benefits of MRP

  • High Availability: By ensuring network redundancy, MRP minimizes downtime and supports continuous industrial processes.
  • Fast Recovery: MRP enables quick recovery from network failures. The typical changeover time (reconfiguration time) for Profinet RT and standard Ethernet communication (e.g. TCP/IP) is round about 200 msec
  • Scalability: The ring topology can easily be expanded by adding more devices, allowing the network to grow with minimal complexity.
  • Simplicity: Despite its sophisticated mechanism, MRP is relatively simple to implement and manage, making it an attractive solution for industrial networks seeking to enhance reliability.

Applications of MRP

MRP is particularly beneficial in environments where network reliability is important, such as in manufacturing plants, power generation facilities, and transportation systems. In these settings, the cost of network downtime can be substantial, not only in terms of lost production but also in potential safety risks. MRP provides a safeguard against these risks, ensuring that network communication remains robust even in the face of hardware failures.


The integration of Profinet MRP into industrial networking solutions represents a significant step forward in enhancing network reliability and operational continuity. By providing a fast, automatic recovery mechanism for network failures, MRP helps to minimize downtime and maintain steady communication flows, crucial for the smooth operation of industrial processes. As industries continue to evolve towards more interconnected and automated systems, technologies like Profinet MRP will play an essential role in ensuring that these systems remain resilient, safe, and reliable.