Allen-Bradley 1756-CNB ControlNet Bridge Module

The Allen-Bradley 1756-CNB ControlNet Bridge Module is a single-slot ControlLogix interface that links a 1756 backplane to a ControlNet network, enabling real-time data exchange between a ControlLogix controller and remote I/O devices on ControlNet. The module provides a dedicated ControlNet communications path with support for 40–48 ControlNet connections, and it operates over ControlNet’s standard network speed, making it suitable for moderate to large ControlNet deployments. As a bridge, it sits in the local chassis and relays I/O data to and from the ControlNet network, allowing remote racks to be connected to a ControlLogix system. It is part of the ControlNet Bridge family and is commonly used to integrate field devices such as I/O modules, sensors, actuators, and drives on ControlNet with a ControlLogix controller, enabling centralized program control and synchronized network timing across the control system. For systems requiring redundancy, the 1756-CNBR is the redundant-bridge counterpart; ensure the correct option matches your backplane architecture and network topology. When configuring ControlNet with this module, use standard Rockwell Automation practices and compatible RSNetWorx for ControlNet tooling to map I/O and define network parameters.