Purchase now: Allen-Bradley 1756-RM2K Redundancy Module
Purchase now: Atlantechdrives provides you the 1756-RM2K, a premium, enhanced-speed redundancy communication module engineered by Rockwell Automation for high-availability ControlLogix 1756 systems. In critical infrastructure—such as municipal water treatment plants, massive chemical reactors, and continuous power generation facilities—a single CPU failure could result in catastrophic environmental damage or millions of dollars in lost production. The 1756-RM2K completely eliminates this single point of failure. By installing one RM2K module in a primary chassis and another in a secondary chassis, connected via a dedicated fiber optic link, this module continuously cross-loads the entire state of the active PLC program at blistering speeds of up to 1000 Mbps. If the primary controller, power supply, or chassis suffers a hardware failure, the 1756-RM2K executes a «bumpless transfer,» instantly handing over full machine control to the secondary chassis in milliseconds without dropping any I/O connections. Crucially, the «K» designation means this specific module features a factory-applied conformal coating, providing immense resistance against corrosive gases, high humidity, and airborne particulates.
Technical Specifications of the 1756-RM2K
The 1756-RM2K is an «Enhanced» redundancy module, offering vastly superior cross-loading bandwidth compared to the legacy 1756-RM, allowing it to synchronize massive programs running on modern L7 and L8 processors without causing network latency.
- Part Number: 1756-RM2K
- Platform: ControlLogix 1756 System
- Function: Enhanced High-Availability Redundancy Cross-Loader
- Environmental Protection: Conformal Coated (Harsh Environment Rated)
- Communication Speed: 1000 Mbps (Gigabit) across dedicated fiber link
- Connector Type: SFP Transceiver with LC Fiber Optic ports
- Compatible Fiber Cable: 1756-RMCx (available in 1, 3, or 10-meter lengths)
- Backplane Current Draw: 1.16 A at 5.1V DC
Expert Installation Advice: Fiber Optic Hygiene and RMC Cables
The synchronization between the primary and secondary chassis relies entirely on the integrity of the fiber optic link connecting the two 1756-RM2K modules. Expert Tip: You must connect the two modules using official Rockwell 1756-RMC1, RMC3, or RMC10 fiber optic patch cords. Because these cables transmit gigabit data via light, absolute cleanliness is mandatory. Before inserting the LC connectors into the RM2K’s SFP transceivers, you must meticulously clean the fiber tips using an industrial fiber optic cleaning pen. A single speck of microscopic dust on the ferrule can severely attenuate the light signal, causing the redundancy cross-load to fail, leaving your plant vulnerable. Additionally, never route the fiber cable tightly around sharp corners; exceeding the minimum bend radius will fracture the internal glass core.
Maintenance: Firmware Synchronization and Firmware Upgrades
Maintaining a ControlLogix redundancy system requires strict adherence to firmware compatibility rules. The 1756-RM2K modules in both the primary and secondary chassis must absolutely be running the exact same firmware revision. Furthermore, the controllers (e.g., L73s) and the EtherNet/IP communication bridges (e.g., EN2Ts) in both chassis must also match perfectly. One of the massive maintenance advantages of the 1756-RM2K architecture is the ability to perform a «locked-in» firmware upgrade. Maintenance engineers can update the firmware of the secondary chassis while the primary chassis continues to run the factory, and then command a manual switchover to the newly updated chassis without ever stopping production.
Frequently Asked Questions (FAQs)
Q: What is the difference between the 1756-RM2 and the 1756-RM2K?
A: The modules are functionally identical. However, the «K» variant has a specialized conformal coating applied to its internal printed circuit boards. This is strictly required for installations in harsh environments with high humidity or corrosive gases (like H2S in wastewater plants) to prevent premature electrical shorts.
Q: Can the 1756-RM2K synchronize standard I/O modules placed in the same chassis?
A: No. In a standard ControlLogix redundancy architecture, the primary and secondary chassis must contain only the Power Supply, Controller, RM2K module, and Communication Bridge modules (like EN2Ts). All physical I/O modules must be located in remote chassis connected via the EtherNet/IP or ControlNet network.
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This conformal-coated redundancy module is essential for high-availability systems using ControlLogix L73 series processors.
