1756-CN2RXT | Allen Bradley ControlLogix ControlNet Redundant Bridge Module

Product Overview

The Allen Bradley 1756-CN2RXT functions as a high-performance ControlNet communication bridge within the ControlLogix platform. This module enables deterministic, repeatable data transfers between controllers and I/O chassis. As a 100% Brand New original XT (Extended Temperature) version, it features specialized hardening and conformal coating to survive extreme industrial climates where standard networking hardware fails. It provides dual BNC ports for media redundancy, ensuring uninterrupted data flow during a single cable failure.

Part Number Breakdown

The 1756-CN2RXT code indicates specific high-availability and environmental capabilities:

• 1756: Identifies the ControlLogix system architecture.

• CN: Specifies the ControlNet communication protocol.

• 2: Represents the enhanced performance series with higher connection capacity.

• R: Indicates Redundancy support (Dual BNC ports).

• XT: Signifies Extreme Environment hardening (Extended temperature and conformal coating).

Technical Specifications

The following data highlights the module's electrical and networking performance:

Engineering Advantages

• Redundant Path Reliability: Dual BNC connectors allow for a secondary cable path. If a trunk line sustains physical damage, the 1756-CN2RXT switches to the redundant link instantly without dropping the I/O connection or stopping the process.

• XT Environmental Hardening: The "XT" designation ensures the module operates across a significantly wider temperature range than standard components. The factory-applied conformal coating protects internal circuitry from salt spray, humidity, and corrosive chemical vapors typical in oil and gas or wastewater facilities.

• High Connection Density: Supporting up to 131 total connections, this module manages massive I/O counts and multiple peer-to-peer controller communications simultaneously, reducing the total number of bridge modules required in the chassis.

• Deterministic Data Delivery: Unlike standard Ethernet, ControlNet utilizes a Scheduled Nut (Network Update Time) to guarantee that critical control data arrives at the exact millisecond required, eliminating network jitter in high-speed motion or safety applications.

FAQs

• Can I use the 1756-CN2RXT in a standard 1756-A7 or 1756-A10 chassis?

  Yes. The module fits into any standard ControlLogix chassis. However, to fully leverage the "XT" environmental benefits, we recommend installing it within an XT-rated chassis and enclosure.

• Does this module require a specific firmware version?

  Yes. Enhanced modules like the 1756-CN2RXT require specific firmware revisions to unlock the 128-connection capacity. Always check your RSLogix 5000 or Studio 5000 project version for compatibility before installation.

• What is the primary difference between this and the standard 1756-CN2R?

  The 1756-CN2RXT provides the exact same communication functionality as the 1756-CN2R but adds conformal coating and extended temperature hardware. Use the XT version for installations subject to thermal extremes or corrosive atmospheres.

• Is this a factory-sealed unit?

  Absolutely. We supply this 1756-CN2RXT as 100% Brand New original stock in the original manufacturer's packaging with a valid UPC (612598554836).