Allen-Bradley 1756-CNBR ControlNet Bridge Redundant

The Allen-Bradley 1756-CNBR ControlNet Bridge Redundant is a redundant bridge module for ControlNet networks within Rockwell Automation’s ControlLogix ecosystem. It performs the same bridging function as the standard 1756-CNB, connecting a ControlNet network to a ControlLogix backplane while adding redundant media to improve reliability and availability. The module supports 40–48 ControlNet connections, enabling wide-scale bridging between ControlNet devices and the ControlLogix controller and ensuring deterministic data flow. In a redundant controller chassis, the CNBR provides automatic failover between primary and secondary ControlNet paths, helping to maintain communication when a media fault occurs. Typical uses include manufacturing automation and process control environments where remote I/O, sensors, and actuators rely on continuous ControlNet communication to the controller. The CNBR is designed to work alongside other 1756-series modules in a ControlLogix rack and is managed according to Rockwell’s redundancy documentation for ControlNet bridges, including configuration and diagnostic practices to monitor bridge health and maintain uninterrupted data exchange.