Buy now: Allen-Bradley 1756-RMC3 ControlLogix Redundancy Module Cable
Atlantechdrives provides you the 1756-RMC3, a 3-meter (9.84 feet) industrial fiber-optic synchronization cable. This cable is specifically designed to connect primary and secondary 1756-RM or 1756-RM2 redundancy modules when the chassis are located in different sections of a cabinet or in separate adjacent enclosures.
- Length: 3 Meters (9.84 feet)
- Transmission: Noise-immune Fiber-Optic
- Application: Chassis Redundancy Synchronization
- Durability: Reinforced jacket for industrial routing
- Module Compatibility: 1756-RM, 1756-RM2, 1756-RMXT
Technical Superiority: Extended Reach Redundancy
The 1756-RMC3 allows for greater flexibility in control cabinet layout. While the shorter RMC1 cable requires chassis to be mounted side-by-side, the 3-meter 1756-RMC3 provides the extra length needed to route the synchronization link through cable ducts or between different racks. This length is particularly useful in complex systems where heat management or physical space constraints require the primary and secondary processors to be separated. Despite the increased length, the 1756-RMC3 maintains the ultra-low latency required for the 1000 Mbps synchronization link. It ensures that the secondary controller’s tag database is updated in real-time, allowing for a seamless switchover in less than 20ms should the primary rack fail.
Expert Tips: Routing and Interference Management
When routing the 1756-RMC3, avoid running it directly alongside high-voltage AC cables if possible, although the fiber itself is immune to EMI, the physical jacket should be protected from mechanical abrasion. Use dedicated plastic conduits to prevent the cable from being snagged or stepped on during maintenance. In the Studio 5000 Redundancy Module Tool, you can monitor the «Link Quality.» If you see a high rate of retries, it may indicate that the 1756-RMC3 has been bent beyond its limit or that a connector has been contaminated with industrial oils.
Maintenance and Longevity in Large Cabinets
For the 1756-RMC3, maintenance is largely preventative. During system audits, ensure the «Service Loop» (the extra length of the cable) is neatly coiled and secured with loose velcro ties—never use tight plastic ties. This prevents stress on the module ports. If a switchover occurs unexpectedly, checking the fiber link with an optical power meter can help rule out the 1756-RMC3 as a point of failure. Because the 3-meter length is less common than the 1-meter, having a spare 1756-RMC3 is critical to avoid long lead times during a system emergency.
FAQs
Q: Can the 1756-RMC3 be cut and spliced to a shorter length?
A: No. The 1756-RMC3 is factory-terminated and certified. Splicing will degrade the signal and void the redundancy certification.
Q: Does it support both 1756-RM and RM2?
A: Yes, it is the standard synchronization cable for both generations of redundancy modules.
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For redundant chassis placed at a distance, this 3-meter fiber cable ensures high-speed data sync between 1756-RM modules.
