Omron CJ1W-DRM21 Operation Manual page 196

6 Message Communications
6-2-1 Sending Explicit Messages
The command code 28 01 can be used to send explicit DeviceNet messages to OMRON special slaves
and DeviceNet masters/slaves made by other manufacturers.
NJ-series CPU Unit
SendCmd
Use 28 01 for the
command code.
The local DeviceNet Unit is specified as the destination in the communications instruction in the PLC's
user program (not the OMRON Special Slave or DeviceNet device made by another manufacturer), and
the node address of the actual destination (i.e., the DeviceNet Slave or Master made by another manu-
facturer) is specified in the command data for the explicit message send command.
Command
CPU Unit
Send
Cmd
Explicit message
OMRON special slave
or master not by OMRON
or slave not by OMRON
Precautions for Correct Use Precautions for Correct Use
Depending on the network status, the destination slave may not always accept an explicit mes-
sage. Always perform retry processing when sending explicit messages.
EXPLICIT MESSAGE SEND (28 01)
EXPLICIT MESSAGE SEND will send an explicit DeviceNet message to the specified class and receive
a response.
Command Block
28 01
Command
Code
Destination Node Address
6-8
Explicit
Header
message
Header Response
SendCmd instruction:
Input variable DnetAdr:
InDNetAdr.NetNo: Destination network address. Set 0 (local network).
InDNetAdr.NetNo: Destination node address. Set 0 (communications within local PLC).
InDNetAdr.UnitNo: Destination unit address. Set unit number +16#10.
Class ID Instance ID
Service Code
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
DeviceNet Unit
Header
DeviceNet
network
Header
534 bytes max.
Service Data
OMRON special slaves or
Slave or Master by other
manufacturer
Explicit
message
Response