Allen-Bradley 1756-CNBR/E User Manual

Rockwell Automation Publication CNET-IN005A-EN-P - May 2011 29
Chapter 3
Redundant Media
These ControlNet bridge modules support redundant media:
• 1756-CN2R/B
• 1756-CN2RXT
• 1756-CNBR/E
• 1768-CNBR
Use Redundant Media
You can run a second trunk cable between ControlNet nodes for redundant
media. With redundant media, nodes send signals on separate trunks. The
receiving node compares the quality of the two signals and permits use of the
better signal while retaining the other signal on a back-up cable should the
primary trunk cable fail.
Trunk cables on a redundant cable link are defined by the segment number and
the redundant trunk-cable letter.
Actual ControlNet products are labeled with these icons:
The shaded icon represents redundant media.
In this example, the redundant trunk cable is trunk cable B.
Topic Page
Use Redundant Media 29
IMPORTANT
ControlNet redundant media can tolerate only one fault. If there is a fault
on both channel A and B, network integrity is not guaranteed.

Allen-Bradley 1756-CNBR/E Specifications

General

Brand	Allen-Bradley
Model	1756-CNBR/E
Category	Controller
Language	English