Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 880

Network Instructions
Note
1,2,3...
This example shows communications from a PLC to a personal computer.
PLC to computer
Communications to a Serial Port in the Network
These examples show communications from a PLC to serial ports in devices
in the network. The first shows communications to serial ports in devices in
another PLC (the CPU Unit, CPU Bus Unit, or Inner Board) and the second
shows communications to a serial port within the CPU Rack itself.
Through the network
Within the CPU Rack
Communications can span up to 8 network levels, including the local network.
(The local network is the network where the communications originate.)
SEND(090),
RECV(098), or
CMND(490)
Bridge or gateway
Network 1
(local network)
In order to communicate through the network, it is necessary to register a
routing table in each PLC's CPU Unit which indicates the route by which data
will be transferred to the desired node. Each routing table is made up of a
local network table and a relay network table.
1. Local network table
This table shows the unit numbers and network addresses of the nodes
connected to the local PLC.
2. Relay network table
This table shows the node numbers and network addresses of the first re-
lay nodes to destination networks that are not connected to the local PLC.
Bridge or gateway
Network 3
Network 2
Section 3-24
847