The Allen-Bradley 1756-CNBR/D is a ControlLogix ControlNet Redundant Bridge Module designed to provide high-speed, reliable communication between different ControlLogix chassis over a ControlNet network. This module ensures network integrity and data availability by supporting redundant media paths, making it ideal for critical industrial automation applications where system uptime is paramount. It installs in any available slot of a ControlLogix chassis and facilitates the transfer of I/O data and messages, enabling seamless integration and control within a distributed architecture. The Series D revision offers enhanced performance and features for demanding control environments.