The Parallel Redundancy Protocol (PRP) is standardized in IEC 61439 Part 3. This international standard enables data communication without switch-over times for the first time. This provides maximum reliability for your information transmission. PRP network redundancy is based on two independent, active paths between two devices. The sender uses two independent network interfaces which send the same data simultaneously. The redundancy control protocol therefore makes sure that the recipient only uses the first data packet and discards the second. If just one packet is received, the recipient knows that a failure has occurred on the other path.
PRP uses two independent networks of any topology and is not limited to ring networks. Redundant rings or even networks without any redundancy can be used in the two independent parallel networks. The big advantage of PRP is uninterrupted switch-over which avoids any switch-over time in the event of an error and therefore provides maximum possible availability.