Product Details
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:
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1756: Identifies the ControlLogix system architecture.
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CN: Specifies the ControlNet communication protocol.
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2: Represents the enhanced performance series with higher connection capacity.
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R: Indicates Redundancy support (Dual BNC ports).
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XT: Signifies Extreme Environment hardening (Extended temperature and conformal coating).
Technical Specifications
The following data highlights the module's electrical and networking performance:
| Feature | Specification |
| Communication Rate | 5 Mbps |
| Logix Connections | 128 |
| Max Supported Connections | 131 |
| Max Number of Nodes | 99 |
| Backplane Voltage | 5.1V DC |
| Backplane Current | 1.3 Amps |
| Power Dissipation | 6.6 Watts |
| Slot Width | 1 (Single Slot) |
| Chassis Location | Any Slot |
| Weight | 0.31 lbs (0.14 kg) |
Engineering Advantages
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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.
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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.
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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.
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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
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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.
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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.
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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.
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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).
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Mastering PLC Programming: Best Practices for Robust Industrial Automation
Writing clean PLC code requires discipline, especially regarding memory management. Avoid overusing SET and RESET instructions, as they often complicate debugging. If multiple rungs control the same bit, troubleshooting becomes a nightmare. Instead, focus on energizing a bit in only one location. If your logic requires complex conditions, use branches within a single rung. This approach keeps your code readable, maintainable, and significantly easier to audit during downtime.
PLC vs. HMI: Distinguishing the Brain from the Interface in Industrial Automation
In the realm of industrial automation, distinguishing between a Programmable Logic Controller (PLC) and a Human-Machine Interface (HMI) is fundamental. While both devices work in tandem, they serve distinct purposes. The PLC acts as the "brain" of the operation, executing logic, whereas the HMI serves as the "eyes," allowing operators to monitor and interact with the system. Understanding this synergy is essential for any professional designing robust factory automation solutions.
Selecting the Right Industrial Automation Solution for Modern Manufacturing
Choosing an effective industrial automation system starts with a thorough process audit. You must identify tasks that are repetitive, labor-intensive, or prone to human error. Not every process requires high-level automation; therefore, prioritize operations that directly impact throughput and quality. By scoping your needs accurately, you avoid over-investing in unnecessary technology. A balanced approach ensures that your capital expenditure aligns with measurable gains in operational efficiency.