Allen-Bradley controllogix 1756-L55M12, User Manual

Page: 24 / 142

Publication 1756-UM001G-EN-P - January 2007
24 Communicate over Networks
EtherNet/IP Network 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 compared to
unconnected messages.
All EtherNet/IP connections are unscheduled. An unscheduled
connection is triggered by the requested packet interval (RPI) for I/O
control or the program, such as a MSG instruction. Unscheduled
messaging lets you send and receive data when needed.
The 1756 EtherNet/IP communication modules support 128 CIP
(Common Industrial Protocol) connections over an EtherNet/IP
network.
LINK NET OK LINK NET OK
Switch
Distributed I/O
1756-ENBT Module
(as an adapter) with 1756
I/O Modules
1794-AENT Adapter with
1794 I/O Modules
Workstation
CompactLogix Controller
with Integrated
EtherNet/IP Port
ControlLogix
Controller with
1756-ENBT
Module
FlexLogix Controller with
1788-ENBT Module
1734-AENT Adapter with
1734 I/O Modules
PowerFlex 700S AC
Drive with DriveLogix