Figure 84: Prp Networks Using Rstp / E-Mrp - ABB UniGear Series Engineering Manual

Network Redundancy
IEC 61850 standard specifies network redundancy that improves the system availability for
substation communication. It is based on two complementary protocols defined in the IEC
62439-3 standard: Parallel Redundancy Protocol and High Availability Seamless Redundancy
protocol. Both protocols can overcome failure of a link or switch with zero-switchover time. In
both protocols, each node has two identical Ethernet ports for one network connection. They
rely on the duplication of all transmitted information and provide zero-switchover time if
links or switches fail, thus fulfilling all the stringent real-time requirements of substation au-
tomation. The choice between these two protocols depends on the application and the re-
quired functionality.
Parallel Redundancy Protocol (PRP) networks using Rapid Spanning Tree Protocol (RSTP) /
Fast Media Redundancy Protocol (E-MRP)
In PRP, each node is attached to two independent networks operated in parallel. The net-
works are completely separated to ensure failure independence and can have different topol-
ogies. Both networks operate in parallel, thus providing zero-time recovery and continuous
checking of redundancy to avoid failures. The PRP1 redundancy is supported by Relion ® 615
(RED615 only via fiber optic interfaces), 620 and 640 series. SCADA system can be connected
to PRP networks via Redbox or directly if PRP redundancy is supported by SCADA.

Figure 84: PRP networks using RSTP / E-MRP

62 1V LG 5 00007 E