GE L90 Instruction Manual page 221

CHAPTER 5: SETTINGS
PRP uses specialized nodes called doubly attached nodes (DANPs) for handling the duplicated frames. DANP devices have
an additional module, called a Link Redundancy Entity (LRE). LRE is responsible for duplicating frames and adding the
specific PRP trailer when sending the frames out on the LAN, as well as making decisions on received frames as to which
one is sent up the OSI stack to the application layer and which one is discarded. LRE is responsible for making PRP
transparent to the higher layers of the stack.
In addition, there is a second type of specialized device used in PRP networks, called RedBox, with the role of connecting
Single Attached Nodes (SANs) to a redundant network.
UR relays implement the DANP functionality. The RedBox functionality is not implemented.
The original standard IEC 62439-3 (2010) was amended to align PRP with the High-availability Seamless Redundancy (HSR)
protocol. To achieve this, the original PRP was modified at the cost of losing compatibility with the PRP 2010 version. The
revised standard IEC 62439-3 (2012) is commonly referred to as PRP-1, while the original standard is PRP-0. The UR relays
support PRP-1.
The relay implements PRP on two of its Ethernet ports, specifically Ports 2 and 3 of the CPU module. Use the previous
section (network port configuration) to configure PRP.
PRP is purchased as a separate option. If purchased (valid order code), PRP can be enabled in configuration through a
setting available on the network configuration menu, REDUNDANCY, which already has the capability of enabling failover
redundancy. The options on this setting must be changed to accommodate two types of redundancy: failover and PRP.
When REDUNDANCY is set to either failover or PRP, the ports dedicated for PRP (Ports 2 and 3) operate in redundant mode.
In this mode, Port 3 uses the MAC, IP address, and mask of Port 2.
5.3.4.7 IPv4 route table
SETTINGS  PRODUCT SETUP  COMMUNICATIONS  IPv4 ROUTE TABLE 1(6)
 IPv4 ROUTE TABLE

A default route and up to six static routes can be configured.
The default route is used as the last choice when no other route towards a given destination is found.
 DEFAULT IPv4 ROUTE

 IPv4 NETWORK
 ROUTE 1
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
Figure 5-8: Example of parallel redundant network
 DEFAULT IPv4 ROUTE


 IPv4 NETWORK

 ROUTE 1

 IPv4 NETWORK

 ROUTE 6
GATEWAY ADDRESS:

127.0.0.1
RT1 DESTINATION:

127.0.0.1
Range: standard IPV4 unicast address format
Range: standard IPV4 address format
PRODUCT SETUP
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