User guide

46 Rockwell Automation Publication 1768-UM002C-EN-P - April 2012
Chapter 4 Communicate over Networks
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 EtherNet/IP communication modules support 64 Common Industrial
Protocol (CIP) connections over an EtherNet/IP network.
EtherNet/IP Communication Example
This example illustrates the following:
• The controllers can produce and consume standard or safety tags between
each other.
• The controllers can initiate MSG instructions that send/receive standard
data or configure devices.
(1)
• The EtherNet/IP communication module is used as a bridge, letting the
safety controller produce and consume standard and safety data.
• The personal computer can upload/download projects to the controllers.
• The personal computer can configure devices on the EtherNet/IP
network.
Figure 8 - EtherNet/IP Communication Example
(1) Compact GuardLogix controllers do not support MSG instructions for safety data.
Computer with Standard
Ethernet Port
ControlLogix®
Controller
Compact GuardLogix Controller with
1768-ENBT Module
Distributed 1734 POINT I/O™
with 1734-AENT Ethernet
Adapter
1791ES-IB8XOBV4
PanelView™ Plus Terminal with
Built-in Ethernet Port
PowerFlex® 700S AC
Drive with DriveLogix™
Software
EtherNet Switch