Omron CS1G/H-CPUxxH Instructions Manual page 890

Network Instructions
1,2,3...
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.
Note Communications can span up to 3 network levels, including the local network.
(The local network is the network where the communications originate.)
SEND(090),
RECV(098), or
CMND(490)
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 aren't connected to the local PLC.
Communications to a Host Computer (Host Link)
By issuing a SEND(090), RECV(098), or CMND(490) instruction to a serial
port set to Host Link mode, the necessary Host Link header and terminator
will be attached to the FINS command and the command will be sent to the
host computer.
PLC to computer
Through the network
Within the CPU Rack
Bridge or gateway
Network 2
Section 3-25
Bridge or gateway
Network 3
869