Allen-Bradley 1756-RM2 Redundancy Module

Series#: AllenBradley

Product Details

1756-RM2 ALLEN-BRADLEY ControlLogix Redundancy Module – seamless chassis-to-chassis backup for critical processes.
Supports automatic failover with zero data loss, ensuring maximum uptime in high-availability industrial networks.
Directly installs into any ControlLogix chassis (1756 series) – no additional cabling required for basic redundancy.
Integrated fiber-optic link for high-speed synchronization between primary and secondary chassis (up to 1 km distance).
Compatible with all ControlLogix controllers (1756-L7x, L6x, L5x) and redundant power supplies.
Reduces system downtime by 99.9% – ideal for oil & gas, power generation, and water treatment applications.
Guaranteed 100% Original factory condition, offering fast and secure worldwide delivery.

Specification

The 1756-RM2 from ALLEN-BRADLEY is a critical component in the ControlLogix redundancy architecture, designed to provide deterministic failover for mission-critical automation systems. This module pairs with a second RM2 in a redundant chassis to maintain continuous control even during primary controller failure. Using a dedicated fiber-optic connection, the 1756-RM2 synchronizes I/O data, program execution, and communication status with zero packet loss. Engineered for harsh industrial environments, it operates reliably across extended temperature ranges and is fully compatible with all standard ControlLogix backplanes. Below is the detailed technical specification table derived from factory documentation and field-proven performance data.

Parameter	Specification
Product Type	ControlLogix Redundancy Module
Model Number	1756-RM2 (Standard Models)
Compatible Chassis	1756-A4, -A7, -A10, -A13, -A17 (AC/DC Models)
Supported Controllers	1756-L71, -L72, -L73, -L74, -L75, -L61, -L62, -L63, -L64, -L65
Redundancy Type	Active-Standby with automatic failover
Synchronization Link	Dual fiber-optic (ST connector, 62.5/125 µm multimode)
Maximum Fiber Distance	1,000 meters (3,280 feet)
Failover Time	Less than 1 scan cycle (typical < 10 ms)
Data Transfer Rate	100 Mbps full-duplex
Number of Redundant Pairs per System	Up to 8 pairs (16 modules total)
Operating Temperature	0°C to 60°C (32°F to 140°F)
Storage Temperature	-40°C to 85°C (-40°F to 185°F)
Relative Humidity	5% to 95% non-condensing
Power Consumption	5.0 W (typical) from backplane
Backplane Current	1.0 A at 5.1 V DC
Isolation Voltage	30 V continuous, 60 V peak, between fiber and chassis
LED Indicators	OK, ACTIVE, STANDBY, LINK, FAULT
Firmware Compatibility	Revision 20.012 or higher (all standard models)
Certifications	UL 508, CSA C22.2 No. 142, CE, ATEX (Zone 2), IECEx
Weight	0.34 kg (0.75 lb)
Dimensions (H x W x D)	144 mm x 35 mm x 100 mm (5.67 in x 1.38 in x 3.94 in)
Warranty	2 years from date of purchase (factory warranty)