User manual

Rockwell Automation Publication 1769-UM011I-EN-P - February 2013 49
Communicate over Networks Chapter 4
Figure 4 - CompactLogix EtherNet/IP Overview
Connections over an EtherNet/IP Network
You indirectly determine the number of connections the controller uses by
configuring the controller to communicate with other devices in the system.
Connections are allocations of resources that provide more reliable
communication between devices than unconnected messages.
All EtherNet/IP connections are unscheduled. An unscheduled connection is a
message transfer between controllers that is triggered by the requested packet
interval (RPI) or the program, such as a MSG instruction. Unscheduled
messaging lets you send and receive data when needed.
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Workstation
PowerFlex
755 Drive
PanelView Plus Terminal
CompactLogix
Controller with
Integrated
EtherNet/IP Port
CompactLogix
Controller with
Integrated
EtherNet/IP Port
1738-AENT ArmorPoint
EtherNet/IP Adapter with
ArmorPoint I/O Modules
1734-AENT POINT I/O Adapter
with POINT I/O Modules
1756-EN2T ControlLogix EtherNet/IP
Communication Module with
ControlLogix I/O Modules
Switch
Distributed I/O
Modules