Rockwell Automation 20-COMM-ER 20-COMM-ER Dual-Port EtherNet/IP Communication Adapter User Manual - Manual (Page 106)

106 Rockwell Automation Publication 20COMM-UM015B-EN-P - July 2013
Chapter 6 Using Explicit Messaging
About Explicit Messaging
Explicit Messaging is used to transfer data that does not require continuous
updates. With Explicit Messaging, you can configure and monitor a slave device’s
parameters on the network.
Important: When an explicit message is performed, by default no
connection is made since it is an ‘unconnected’ message. When
timing of the message transaction is important, you can create a
dedicated message connection between the controller and drive
by checking the ‘Connected’ box on the Communications tab
message configuration screen during message setup. These
message connections are in addition to the I/O connection.
However, the trade off for more message connections is
decreased network performance. If your application cannot
tolerate this, do not check the ‘Connected’ box, which is
recommended.
Important: PowerFlex 7-Class drives have explicit messaging limitations.
Table 17 shows the EtherNet/IP Object Class code
compatibilities for these drives.
Table 17 - Explicit Messaging Class Code Compatibility with Drives
Performing Explicit
Messages
There are five basic events in the Explicit Messaging process. The details of each
step will vary depending on the type of controller being used. See the
documentation for your controller.
Important: There must be a request message and a response message for all
Explicit Messages, whether you are reading or writing data.
EtherNet/IP Object
Class Code
PowerFlex
7-Class Drives
Explicit Messaging Function
Parameter Object 0x0F Yes Single parameter reads/writes
DPI Parameter Object
0x93
Yes Single and scattered parameter
reads/writes