Sending Explicit Messages - Omron CJ1W-EIP21 - 10-2010 Operation Manual

Sending Explicit Messages

9-1 Sending Explicit Messages
CS/CJ-series EtherNet/IP Unit
CPU Unit
CMND
(490)
1,2,3...
234
CS/CJ-series EtherNet/IP Units and built-in EtherNet/IP ports can send
explicit messages. Only CIP unconnected message (UCMM) communications
can be used to send explicit messages. Explicit messages can be sent to the
following destinations.
• EtherNet/IP Units made by other manufacturers
• Other PLCs with a CS/CJ-series EtherNet/IP Unit or built-in EtherNet/IP
port
Example
CS/CJ-series CPU Unit
Explicit messages can be sent
Explicit message
Ethernet (EtherNet/IP)
When the destination is another company's EtherNet/IP node, an explicit mes-
sage can be sent to the EtherNet/IP Unit or built-in EtherNet/IP port using
FINS command code 28 01 or 28 10, through the Connection Manager class's
Unconnected Send service, as shown in the following diagram.
Explicit
FINS
message
header
Note: Use 28 01 for the
FINS command code.
FINS Response
header
When sending an explicit message, set the local node's EtherNet/IP Unit or
built-in EtherNet/IP port as the destination of the FINS command, and not the
actual destination (other company's EtherNet/IP node). Specify the node
address of the actual destination in the command data of the explicit message
send command.
There are two ways to send an explicit message send command:
1. CIP UCMM MESSAGE SEND command (28 10)
Messages can be routed through multiple CIP network layers. (Messages
can be routed through 16 network levels. The explicit message send com-
mand may time out if routing is attempted for more than 16 networks.
2. EXPLICIT MESSAGE SEND command for DeviceNet Units (28 01)
This command is compatible with the DeviceNet Unit's explicit message
send command (28 01) in the ladder program. The message must be sent
Other manufacturer's
EtherNet/IP node
CS/CJ-series EtherNet/IP Unit
EtherNet/IP Unit
FINS
header
FINS
header
Section 9-1
CS/CJ-series
CPU Unit
Other company's
EtherNet/IP node
Explicit
message
EtherNet/IP
network
Response