Overview

The Allen Bradley 1756‑CN2R is a ControlNet communication bridge module used within the ControlLogix platform. It enables controllers, I/O modules, and other devices to communicate over a redundant ControlNet network.

The module supports dual BNC ports for redundant media, ensuring continuous operation even if one network path fails. In addition, it can handle up to 100 connections, making it suitable for large and complex automation systems.

Valued for its robust communication, redundancy features, and seamless integration with Rockwell Automation Logix controllers, the 1756‑CN2R is widely deployed in industries requiring high availability and deterministic communication.

Technical Data

Typical Applications

Redundant ControlNet Networks

Provides dual-media communication for high-availability automation systems.

Process Automation

Used in chemical, petrochemical, and refining plants for reliable controller-to-I/O communication.

Power Generation

Ensures deterministic communication in turbine and boiler control systems.

Manufacturing

Applied in automotive, food & beverage, and packaging industries requiring synchronized control.

Critical Infrastructure

Supports redundant communication in mission-critical facilities such as oil & gas pipelines and utilities.

Example:
In a refinery automation system, the 1756‑CN2R ensures continuous communication between controllers and distributed I/O, even if one ControlNet path fails. Its ability to manage up to 100 connections makes it suitable for large-scale automation networks.

FAQ

Q1: What is the primary function of the 1756‑CN2R?
A1: It provides redundant ControlNet communication for ControlLogix systems.

Q2: How many connections can it handle?
A2: It supports up to 100 connections simultaneously.

Q3: What type of ports does it have?
A3: It features two BNC ControlNet ports (A/B) for redundant media.

Q4: Is the module still active?
A4: Yes, it is listed as an Active Mature Product by Rockwell Automation.

Q5: What industries typically use this module?
A5: Energy, petrochemical, manufacturing, and critical infrastructure sectors.