Allen-Bradley 1756-CNBR Control Net Communications Bridge

The Allen-Bradley 1756-CNBR ControlNet Redundant Bridge Module is a ControlLogix-compatible interface that provides a redundant bridge between ControlNet networks and the 1756 backplane, enabling reliable exchange of I/O data and control commands for distributed devices. It offers dual media redundancy via two BNC connectors and supports 40–48 ControlNet connections, designed to maintain network availability in failover scenarios. As a bridge module, it plugs into a ControlLogix chassis and connects a ControlNet network to the controller, functioning as a communications intermediary for data transfer across the network. The CNBR variant represents the redundant option in the ControlNet bridge family, complementing the nonredundant 1756-CNB and is used in applications where uninterrupted ControlNet communication is critical.