1756-RM | Allen Bradley | ControlLogix Chassis Redundancy Link

Allen Bradley 1756-RM Series B ControlLogix Redundancy Module

Product Description

The 1756-RM (1756-RM) Series B is a high-performance redundancy module designed for the Allen-Bradley ControlLogix platform. It serves as the critical synchronization link between a primary and a secondary controller chassis in high-availability systems. By facilitating real-time data crossloading and monitoring the health of the active processor, the 1756-RM (1756-RM) ensures that in the event of a primary controller failure, the secondary system takes control seamlessly without disrupting the process.

This Series B module features enhanced synchronization speeds and improved fiber-optic communication diagnostics over the original Series A. It is essential for mission-critical industrial applications where downtime results in significant financial loss or safety risks. The 1756-RM (1756-RM) operates by scanning the primary chassis state and maintaining an identical image in the secondary chassis, enabling a bumpless switchover that is transparent to the rest of the network and field devices.

Detailed Technical Specifications

The 1756-RM Series B provides robust synchronization with the following engineering specifications:

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model/Catalog Number: 1756-RM

• Series: Series B (Enhanced Redundancy)

• Module Type: Redundancy Module

• Backplane Current (1.2V DC): 4 mA

• Backplane Current (5.1V DC): 1.2 A

• Backplane Current (24V DC): 120 mA

• Power Dissipation: 9 Watts

• Thermal Dissipation: 31 BTU/hr

• Fiber Optic Cable Compatibility: 1756-RMC1 (1m), 1756-RMC3 (3m), 1756-RMC10 (10m)

• Switchover Time: Typically within 10–50 ms (application dependent)

• Isolation Voltage: 30V (continuous), Basic Insulation Type

• Operating Temperature: 0°C to +60°C (32°F to 140°F)

• Storage Temperature: -40°C to +85°C (-40°F to 185°F)

• Compatible Chassis: 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17

• Compatible Controllers: ControlLogix L6 and L7 series (e.g., 1756-L71, L72, L73)