Allen-Bradley 1756-RM ControlLogix Redundancy Module

Product Overview

The Allen-Bradley 1756-RM serves as the primary hardware link for high-availability ControlLogix systems. This redundancy module synchronizes data between a primary and secondary chassis, ensuring an instantaneous switchover if a controller failure occurs. We provide this unit in 100% Brand New, original condition, ensuring your mission-critical processes benefit from factory-sealed, unpowered hardware for maximum system longevity. It supports complex architectures by managing cross-loading of data without interrupting the control loop.

Technical Specifications

Engineering Advantages

• High-Speed Data Synchronization: The 1756-RM manages the state-data transfer between the primary and secondary ControlLogix chassis. It ensures that the backup controller remains ready to assume control within milliseconds, preventing process bumps or safety shutdowns.

• Flexible Chassis Integration: This module fits into any available slot in a 1756 ControlLogix chassis. It bridges the redundancy link via fiber-optic cables (sold separately), isolating the two chassis and protecting the system from electrical surges or localized power failures.

• Diagnostic Transparency: The 1756-RM provides real-time status updates to the controller. Engineers monitor synchronization health directly through Studio 5000, allowing for proactive maintenance before a system switchover becomes necessary.

• Rugged Thermal Engineering: A specialized heat-sink design limits power dissipation to 9 Watts. This thermal efficiency permits the module to operate in high-density racks without exceeding the T4 temperature code, protecting adjacent I/O and processor modules from heat stress.

• Power Supply Versatility: The module works seamlessly with both standard (1756-PA72, -PB75) and redundant (1756-PA75R, -PB75R) power supplies. This adaptability allows you to design a fully redundant power and control architecture tailored to your facility's risk profile.

FAQs

• Does this 1756-RM ship in the original factory box?

  Yes. We guarantee this unit is 100% Brand New. It arrives in its original Allen-Bradley factory packaging with intact security seals, ensuring you receive a component that has never seen field service.

• Can I use the 1756-RM in the same chassis as my I/O modules?

  In a standard redundancy configuration, the redundancy chassis typically contains only the 1756-RM, the controller(s), and communication modules (like the 1756-EN2T). This isolates the control core from field-side I/O disturbances.

• How many 1756-RM modules do I need for a redundant system?

  A complete redundant pair requires two 1756-RM modules—one for the primary chassis and one for the secondary chassis—connected via a fiber-optic cable.

• What cable type connects two 1756-RM modules?

  The modules utilize 1756-RMC series fiber-optic cables. We recommend selecting the cable length (1m, 3m, or 10m) based on your specific cabinet layout to ensure optimal signal timing and reduced electromagnetic interference.