iRBX6GF User’s Manual
UM-iRBX6GF-4.5.1-EN.docx
Pages 22 of 119
7.2
PRP
PRP (Parallel Redundancy Protocol) is a protocol standardized by IEC 62439-3 Clause 4 [3].
For more information, refer to:
http://en.wikipedia.org/wiki/Parallel_Redundancy_Protocol
Each node is connected to two separated and parallel networks (see the figure below). The nodes
send two copies of each frame, one over each network. When a RedBox’s node (Redundancy Box’s
node) receives a frame, it accepts the first copy and discards the second, eliminating the duplicate
frame.
7.3
HSR-PRP (Dual RedBox Mode)
HSR-PRP mode, also called Dual RedBox mode, is used to bridge HSR and PRP networks. In this mode,
two different RedBoxes connect to LAN A and LAN B of the PRP network. Two ports connect to the HSR
ring and one port connects to one of the two PRP LANs. The traffic on the upstream interlink port
connecting the RedBox to the PRP network is PRP-tagged. In HSR-PRP mode, the RedBox extracts data
from the PRP frame and generates the HSR frame using this data and performs the reverse in the opposite
direction. To avoid loops and use network bandwidth effectively, the Redbox does not transmit frames
already transmitted in same direction.