Rockwell Automation 1734-AENT, Series B POINT I/O EtherNet/IP Adapter Module User Manual - Manual (Page 18)

8 Rockwell Automation Publication 1734-UM018B-EN-P - October 2013
Chapter 1 Overview of the 1734 POINT I/O EtherNet/IP Adapter
Rack-optimized connections reduce the total number of connections needed to
transfer data when using many digital I/O modules in a system. The following
example illustrates the benefit of rack-optimized connections.
Assume you set up a system that contains eight digital I/O modules interfaced to
an adapter. If you use direct connections to transfer data to each of the these I/O
modules, you need eight connections to transfer all of the data, one to each of the
eight I/O modules. If you use a rack-optimized connection to transfer the data,
you only need a single connection – the connection to the I/O adapter.
See the EtherNet/IP Embedded Switch Technology Application Guide,,
publication
ENET-AP005 , for more information on connections.
Mixing Rack-optimized and Direct Connections
You can mix communication formats for different I/O modules communicating
through the same adapter. I/O modules set up to use rack optimization
communicate at the rate of the RPI configured for the adapter. I/O modules
configured for direct communication communicate at their own individual RPIs
and ignore the rack-optimized RPI.
Before You Begin To effectively use your adapter, note the following considerations.
Determine Compatibility
If using the adapter with a 1756-ENBT module or 1788-ENBT module, use the
following required firmware revisions for these bridge modules:
• 1756-ENBT firmware revision 2.3 or later
• 1788-ENBT firmware revision 1.33 or later
If you use the BootP Utility to assign IP addresses to the adapter, use revision
2.3.2 or later.
IMPORTANT Although rack-optimized connections offer an efficient way to use
resources, there are a few limitations on their use:
• You can use only rack-optimized connections to send data to and
from digital I/O modules. Analog or speciality I/O requires direct
connections.
• All data is sent at the same time as the RPI rate of the I/O adapters.
If the update rate required for a digital module is different from the
RPI of the rack-optimized connection, a direct connection to that
digital I/O module is required.