Omron CJ - INSTRUCTIONS REFERENCE MANUAL 07-2009 Reference Manual page 895

3. Instructions
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.
• Local network table: This table shows the unit numbers and network addresses of the nodes
• Relay network table: This table shows the node numbers and network addresses of the first relay
Unsolicited Communications with a Host Computer Connected via Host
Link
By executing a SEND(090), SEND2(491), RECV(098), RECV2(492), CMND(490), or CMND2(493)
instruction for 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.
Host computer connected to
the CPU Unit's built-in port
Host computer
Host Link
FINS
command
Host Link header and address
Note Host Link communications can be sent through the network. In this case, the FINS command travels through
the network normally. When the command reaches the Host Link system, the necessary Host Link header
and terminator are attached to the FINS command and the command is sent to the host computer.
858
connected to the local PLC.
nodes to destination networks that are not connected to the local PLC.
Host computer connected to a
Serial Communications Board
Host computer
To port
CPU Unit
Host Link
Host Link FCS
and terminator
Host computer
Host Link header
Host Link FCS
and terminator
Host computer connected to a
Serial Communications Unit
(CS Series only)
To port
Host Link
Serial Communications
Board
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Host computer
To port
Serial Communications
Unit