What is MRP (Media Redundancy Protocol) required for? What happens with a PROFINET participant when the power supply fails?

PROFINET participants mostly have 2 ports for the PROFINET cabling. The two ports are connected with one another by an internal 2-port switch component. If the power supply of a PROFINET participant fails, the communication is interrupted at this point in a network line. One can get around this problem with ring cabling using MRP technology.

If the power supply of a PROFINET switch fails, the communication with all participants connected to this switch is no longer possible.

This behavior is clearly different from that of PROFIBUS networks!