Overview; Outline Of Message Communications - Omron CJ1W-DRM21 Operation Manual

6 Message Communications
6-1

Overview

Message communications enable messages to be set between nodes on a DeviceNet network when
required by system conditions. It is possible for messages to be sent between a PLC and a DeviceNet
master or slave made by another company. You can use them to send/receive data; read time data,
error logs, and other data; or control operation, e.g., refreshing with user-specified values.
There is one type of messages: Explicit messages.
6-1-1

Outline of Message Communications

Explicit message communications

Overview

General-purpose message communications that uses DeviceNet protocol
Remote • DeviceNet masters and slaves from other companies
devices
• C200H-series DeviceNet Units, CVM1/CV-series DeviceNet Units, and CS/CJ-series DeviceNet
Units
Features • Message communications with DeviceNet devices from other companies can be performed.
• Explicit messages from OMRON PLCs (with C200H-series DeviceNet Units and CVM1/
CV-series DeviceNet Units) can be received. Explicit messages can be sent to OMRON PLCs
(with C200H I/O Link Units).
Message communications functions
Overall Structure
NJ-Series CPU Unit
SendCmd
instruction
(2801 Hex)
Additional Information
If only the message communications function is being used and the remote I/O communications
function is not being used, message communications are possible even if the master function is
disabled. In this case, it is not necessary to register a scan list.
6-2
Explicit message
communications function
DeviceNet Unit
2801 Explicit message
DeviceNet network
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
Explicit
message
function
DeviceNet message communications
Explicit message
Send
Receive