Omron E5ZN-DRT, Operation Manual

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Overview of Explicit Message Communications Section 6-1
6-1 Overview of Explicit Message Communications
6-1-1 Explicit Message Communications
Explicit message communications is a communications protocol for sending
commands from the master as explicit messages, and receiving explicit mes-
sages as responses from the nodes that receive the commands.
Explicit messages can be sent from the master to the DeviceNet Communica-
tions Unit to read and write the Temperature Controller variable area, send
operation commands, and read and write various other functions supported
by the DeviceNet Communications Unit.
Explicit message communications can be used to send and receive data that
is not allocated in the IN and OUT Areas due to word size restrictions, and
data that does not require the frequent refreshing used by the IN Area and
OUT Area.
Use either of the following two methods depending on the application.
Reading/Writing
Temperature Controller
Variable Area Data and
Sending Operation
Commands Send Compoway/F communications commands to Temperature Controllers
by embedding them in explicit messages.
Reading/Writing
Maintenance Information
for the DeviceNet
Communications Unit and
Temperature Controllers Send explicit messages to the DeviceNet Communications Unit.
Note This manual describes the contents of explicit messages that can be sent to
DeviceNet Communications Units. For details on the methods of sending
explicit messages, refer to the operation manual for the DeviceNet Unit being
used as the master.
DeviceNet Unit CPU Unit
Master
(PLC)
IOWR or
CMND
instruction
CompoWay/F communications
command sent to Temperature
Controller (embedded in
explicit message)
Explicit message sent
to DeviceNet
Communications Unit
Slave Slave
E5ZN
Temperature Controller
E5ZN-DRT
DeviceNet Communications Unit
Conversion
Unit
0 Unit
1 Unit
15
CompoWay/F
communications
command