Allen-Bradley 1756-CNBR Bridge Module

The Allen-Bradley 1756-CNBR ControlNet Redundant Bridge Module is a single-slot bridge device for ControlLogix systems that provides redundant interconnection between ControlNet networks within a 1756 backplane chassis. It operates at a 5 Mbps communication rate and supports 40–48 Logix communications connections across the ControlNet network, with a maximum of 64 total connections and up to 99 nodes. Designed for use in industrial automation, the CNBR enables bridging between ControlNet segments with redundancy to help maintain network availability in harsh environments. Key physical specs include a slot width of 1 (location in the chassis can be any slot) and a weight of 0.64 lb (0.293 kg). Power requirements are documented as 5.1 V DC at approximately 970 mA, or 24 V DC at around 1.7 mA, reflecting its low-power ControlNet bridge functionality within a ControlLogix system. This module is compatible with standard ControlNet topologies used by Allen-Bradley controllers and is specifically intended to provide reliable, redundant bridging for ControlNet networks in large automation racks.