Network Instructions - Omron CJ - REFERENCE MANUAL 10-2009 Reference Manual

3. Instructions

Network Instructions

Network Instructions
Overview of Network Communications Instructions
The network instructions can be divided into two types, SEND(090)/SEND2(491)/RECV(098)/RECV2(492)
and CMND(490)/CMND2(493). These instructions are transmitted between Units (CPU Units, CPU Bus
Units, and computers) in a network to transfer data and control operation, such as changing the
operating mode.
Message content
Commands to
transmit/receive data
(FINS command)
Arbitrary commands
(FINS command)
The commands executed by the network instructions are known as "FINS commands" and are used for
communications between FA control devices. (Refer to the CS/CJ Series Communications Commands
Reference Manual (Cat. No. W342) for details on FINS commands.) With FINS commands it is possible
to communicate (by the command/response format) with any Unit in any network or on the CPU Rack
itself just by specifying the network address, node number, and unit number of the destination Unit.
In the following example, a FINS command is sent to the CPU Unit through node number 2 in network
address 00.
Node number 1
Network address 00
(local network)
Network address:
Node number:
Unit address:
868
Instruction
SEND(090)/SEND2(491)
RECV(098)/RECV2(492)
CMND(490)/CMND2(493)
Node number 2
CPU Unit (Rack)
Network address 01
Address of the network (local network = 00 hex)
Logical address in the network
Unit address of the destination Unit
• CPU Unit: 00 hex
• CPU Bus Unit: Unit number + 10 hex
• Special I/O Unit: Unit number + 20 hex
• Inner Board: E1 hex
• Computer: 01 hex
Operation
CPU Unit
Data transmission
SEND(090),
SEND2(491),
RECV(098), or
Data reception
SECV2(492)
CPU Unit
Command sent
CMND(490) or
CMND2(493)
Response returned
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Other device
CPU Unit,
CPU Bus Unit or
computer
Other device
CPU Unit,
CPU Bus Unit, or
computer