Omron CJ Series, Operation Manual

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3-1 Routing Table Overview
3-1-1 Definition of Routing Tables
3-3
Note 1. If there is no local network table and the network is accessed from a
Programming Device or ladder program instruction with the network address = 0,
the CPU Unit will automatically access the network of the Communications Unit
with the lowest unit number in the FINS system.
2. With CX-Integrator version 2.1 or higher, the destination network can be
switched when transferring routing tables. (The FINS system is used in the
example described above.)
For details, refer to
3-2-10 Transferring Routing Tables to a Network PLC
through a Direct Serial Connection .
Relay Network Table
The relay network table indicates the network address and node address of the first
relay node to reach each destination network (final network). When data is being
transmitted across network levels, the data is transmitted to the final network by being
passed through the relay nodes set in the relay network tables.
With the standard table format, up to 20 networks (lines) can be registered in the relay
network table. With the extended table format (see note), up to 64 networks (lines)
can be registered in the relay network table.
Note: The extended table format is supported only for CS/CJ-series CPU Units with unit version
4.0 or later.
Example: In this case, the tables have been set to route communications from network address 1 (local
node: PLC1) to network address 3 (destination node: PLC4).
Relay network tables have been set in the PLCs that are relay nodes in the
communications path (PLCs with multiple Communications Units).
Local node
(source)
PLC1 Destination node
PLC4
Network
address 1
Network
address 2
Network
address 3
Items in the Relay Network Table
The relay network table is made up of the following items.
1) Destination network address
Specifies the address (1 to 127) of the final destination network, which is in
another network level.
2) Relay network address
Specifies the address (1 to 127) of the network containing the first relay node in
the path to the destination network.
3) Relay node address
Specifies the node address of the first relay node in the path to the destination
network.
3) Relay node address
2) Relay network address
1) Destination network address
Local node PLC1
Destination node
Network address 1
Network address 2
Node address 1