The MRP (Media Redundancy Protocol) handles redundancy on a PROFINET ring using one "MRP Manager" node and several "MRP Clients", guaranteeing a failover time below 200 ms in the event of a cable break.
True
MRP is standardised in IEC 62439-2. The MRP Manager (one per ring) monitors both ends of the ring and blocks or unblocks a port to prevent loops; the MRP Clients are all the other switches/devices on the ring and forward the supervisory frames. Standard failover is around 200 ms, with proprietary MRP Fast variants reaching about 30 ms, which is sufficient for most process applications. For critical motion control, MRP is not fast enough and PRP (Parallel Redundancy Protocol), with two parallel networks, is preferred.
On a PROFINET ring, exactly one node must be configured as MRP Manager; misconfiguring two managers (or none) is a classic commissioning mistake that turns a redundant ring into an outage waiting to happen.
PROFINET bank in preparation
The full PROFINET bank isn't available yet. Drop your email to get notified at launch and grab an early-bird discount.
Join the waitlist →See the 9 other PROFINET practice questions
Related questions
- PROFINET defines three device roles: IO Controller (equivalent to the PLC master), IO Device (equivalent to a slave: sensor, actuator) and IO Supervisor (engineering PC used for diagnostics and configuration).1. Architecture · Device-Rollen-Modell
- A GSDML file (Generic Station Description Markup Language) is provided by the manufacturer of a PROFINET IO Device and is imported into the engineering tool (e.g. TIA Portal) to integrate the device into the project.1. Architecture · GSDML
- The PROFINET Update Time of an IO Device is configurable individually depending on the application: typical values range from 1 to 128 ms in RT, and down to 250 us in IRT.2. Real-time classes · Update Time
- PROFINET supports several physical topologies: star (via switches), line (daisy-chain through ports integrated in the devices) and ring (with MRP for redundancy), and they may be combined within the same network.3. Topology & cabling · Unterstützte Topologien
- LLDP (Link Layer Discovery Protocol, IEEE 802.1AB) lets PROFINET devices identify each other and automatically discover the network topology, which is exploited by diagnostic tools such as PRONETA or the TIA Portal Topology Editor.4. Diagnostics · LLDP