ABB ABILITY SSC600 Operation Manual page 9

1MRS758850
information via two Ethernet ports for one logical network connection. Therefore, it is able
to overcome the failure of a link or switch with a zero-switchover time, thus fulfilling the
stringent real-time requirements for the substation automation horizontal communication
and time synchronization.
PRP specifies that each device is connected in parallel to two local area networks. Thus,
each device incorporates a switch element that forwards frames from port to port.
PRP
Each PRP node, called a doubly attached node with PRP (DAN), is attached to two
independent LANs operated in parallel. These parallel networks in PRP are called LAN A
and LAN B. The networks are completely separated to ensure failure independence, and
they can have different topologies. Both networks operate in parallel, thus providing zero-
time recovery and continuous checking of redundancy to avoid communication failures.
Non-PRP nodes, called single attached nodes (SANs), are either attached to one network
only (and can therefore communicate only with DANs and SANs attached to the same
network), or are attached through a redundancy box, a device that behaves like a DAN.
Figure 2. PRP solution
In case a laptop or a PC workstation is connected as a non-PRP node to one of the PRP
networks, LAN A or LAN B, it is recommended to use a redundancy box device or an
Ethernet switch with similar functionality between the PRP network and SAN to remove
additional PRP information from the Ethernet frames. In some cases, default PC
workstation adapters are not able to handle the maximum-length Ethernet frames with the
PRP trailer.
SSC600
Operation Manual
Note: IEC 62439-3:2012 cancels and replaces the first edition published in
2010. These standard versions are also referred to as IEC 62439-3 Edition 1
and IEC 62439-3 Edition 2. The IED supports IEC 62439-3:2012 and it is not
compatible with IEC 62439-3:2010.
Introduction
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