The Allen-Bradley 1756-CNBR is a ControlLogix communication module. This module is a ControlNet Bridge communication module that features Two (2) ControlNet ports supporting simplex and redundant ControlNet network. This module also has 1 Network Access Protocol (NAP) having a physical interface of RJ-45 8-pin with shield. It supports communication rate of 5Mbps and 40-48 ControlNet logical connections.
The Allen-Bradley 1756-CNBR, or ControlNet Bridge Redundancy, is an interface module used for communicating within a ControlNet Network. It is the same as the 1756-CNB but the biggest difference is that the 1756-CNBR has an additional ControlNet port, which will support redundant media. This module has 2 ControlNet BNC port while the 1756-CNB only has one, although both of them have 1 ControlNet RJ45 port.
