Rockwell Automation RECOMM-DNET DeviceNet Adapter for use with DPI AC Drives - Manual (Page 73)

Using Explicit Messaging 7-7
7.4 Running Explicit Messages
There are five basic events in the Explicit Messaging process as
shown in figure 7.4. The details of each step will vary depending on
the controller (ControlLogix, PLC, or SLC). Refer to the
documentation for your controller.
Important: There must be a request message and an response
message for all Explicit Messages, whether you are
reading or writing data.
➀ You format the required data and set up the ladder logic
program to send an Explicit Message request to the scanner
module (download).
➁ The scanner module transmits the Explicit Message
Request to the slave device over the DeviceNet network.
➂ The slave device transmits the Explicit Message Response
back to the scanner. The data is stored in the scanner buffer.
➃ The controller retrieves the Explicit Message Response from
the scanner’s buffer (upload).
➄ The Explicit Message is complete. If you are using a PLC or
SLC, delete the transaction ID so that it can be reused.
Figure 7.4 – Explicit Message Process
Set up and send Explicit
Retrieve Explicit
Message Response
Message Request
Complete Explicit
Message
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