Rockwell Automation 1768-CNxxx ControlNet Communication Modules - Manual (Page 33)

Rockwell Automation Publication CNET-IN005C-EN-P - July 2014 33
Chapter
3
Redundant Media
These ControlNet bridge modules support redundant media:
• 1756-CN2R
• 1756-CN2RK
• 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 33
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.