ABB SM812K01 (3BSE072270R1) – ModuleBus fiber link extender for remote S800 I/O segments

The ABB SM812K01 is designed to carry the S800 I/O ModuleBus over fiber, typically to reach remote I/O clusters or to bypass electrically noisy areas in a plant. From my experience, you pair an SM812K01 on the remote side with an SM811K01 at the controller-side ModuleBus, and you get a stable, noise-immune link that’s far more forgiving than long copper runs. It integrates cleanly with ABB’s 800xA/S800 I/O architecture and, in many cases, is the simplest way to push I/O closer to the process without sacrificing determinism.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days
• Lead time: typically 1 week if in stock; no more than one month at the latest
• Payment: 50% advance; balance due before delivery
• Express delivery: FedEx, UPS, DHL

Key Features

• Fiber-based ModuleBus extension – Moves S800 I/O segments off-cabinet and across long runs while maintaining timing and stability.
• Improved EMI immunity – Optical link helps avoid ground loops and electrical noise that often plague copper in heavy industry.
• Compact DIN-rail form factor – Fits neatly into standard control cabinets without reworking your layout.
• Remote-side device (paired operation) – Typically used with an SM811K01 on the host side for a complete copper-to-fiber-to-copper ModuleBus path.
• 24 V DC utility power – Easy to integrate with standard cabinet power rails; modest power draw.
• Simple diagnostics – Status indicators make it straightforward to verify link state and troubleshoot field issues.

Technical Specifications

Related or Supporting Products

• ABB SM811K01 – Host-side ModuleBus fiber converter; typically paired with SM812K01 for the complete link.
• ABB TB840A – ModuleBus optical interface for S800 I/O; useful when integrating optical segments in larger I/O bays.
• ABB CI854A – PROFIBUS DP communication interface for AC 800M; often found in the same cabinets as S800 I/O expansions.
• ABB TU830 / TU835 MTUs – Mounting and terminal units for S800 I/O modules; provide wiring and field termination.

A maintenance supervisor told us they swapped long copper ModuleBus runs for an SM811/SM812 fiber pair during an outage; noise issues dropped off immediately and the cabinet stayed cooler with better cable routing. That lines up with what we typically see in brownfield upgrades.

Installation & Maintenance

• Cabinet environment – Mount on a 35 mm DIN rail in a clean, dry cabinet. Allow a small air gap for convection and keep ambient within 0–55 °C.
• Power & grounding – Feed with a regulated 24 V DC supply. Tie shields and grounds per ABB S800 grounding practices to avoid loops.
• Fiber handling – Use quality duplex multimode patching with correct polish and bend radius. Clean connectors before mating; avoid tight bends or crushed conduits.
• Wiring – Keep ModuleBus copper stubs short and separated from high-voltage or VFD cables. Label both ends of the fiber to simplify maintenance.
• Safety – De-energize before wiring. Observe ESD precautions when handling modules.
• Routine checks – Inspect link LEDs, verify optical power budgets during PMs, and clean fiber end-faces. Firmware updates are generally not required for this type of unit, but follow ABB service notes if issued.

Quality & Certifications

• CE compliant; typically cULus recognized for control cabinet use
• RoHS and REACH compliant materials
• Manufacturer’s warranty supported; sales warranty provided for 365 days