ABB S800 I/O Modules | TB811 3BSE008568R1 Modulebus Optical Port

Technical Dossier

Product Details And Specifications

ABB S800 I/O Series: Comprehensive Module Range and Technical Overview

The ABB S800 I/O system is a distributed I/O platform engineered for integration with the ABB AC800M controller family, which forms the backbone of ABB's 800xA Distributed Control System (DCS). Deployed across global heavy industry — including petrochemical refineries, nuclear power stations, pulp and paper mills, offshore platforms, and chemical processing plants — the S800 I/O system represents one of the most widely installed distributed I/O architectures in process automation. Its modular backplane design, redundancy support, and PROFIBUS DP / Modulebus optical communication backbone have made it a reference standard for safety-critical continuous process environments. Installed base estimates exceed hundreds of thousands of nodes globally, with active deployments spanning systems commissioned from the mid-1990s through to the present day.

The Evolution of S800 I/O Architecture

The S800 I/O system was introduced alongside the ABB Advant Controller 450 (AC450) and later became the primary I/O subsystem for the AC800M platform. The architecture has passed through several distinct generations:

Generation 1 (mid-1990s): Initial S800 modules were designed for Modulebus communication over copper media. Backplane units such as the TB805 and TB806 supported up to 8 I/O modules per cluster. Communication relied on the CI810 PROFIBUS DP adapter.

Generation 2 (early 2000s): Introduction of optical Modulebus via the TB811 and TB820 series, enabling noise-immune fiber-optic inter-cluster communication over distances up to 80 meters. This generation also introduced the CI840 and CI854 communication interfaces for PROFIBUS DP and HART integration.

Generation 3 (2010s): The S800 I/O system was extended with the S800 I/O xSeries (e.g., AI893, AO890, DI890, DO890), offering higher channel density, improved diagnostics, and compatibility with the AC800M High Integrity (AC800M HI) controller for SIL 2/3 safety applications. The TB840A and TB845 backplane units support redundant Modulebus configurations.

Current Status: The S800 I/O system is in its mature/sustaining phase. ABB continues to manufacture and support the platform, but new greenfield projects increasingly specify the S900 I/O or ABB Ability™ System 800xA with Ethernet-based I/O. For existing installations, ABB and authorized distributors such as DriveKNMS provide long-term lifecycle support, including spare parts sourcing for discontinued module variants.

S800 I/O Full Catalog & Functionalities (SKU List)

Backplane & Modulebus Infrastructure

• TB805 3BSE008516R1: S800 I/O baseplate, 8-slot, copper Modulebus, standard cluster unit
• TB806 3BSE008534R1: S800 I/O baseplate, 8-slot, with integrated power distribution rail
• TB811 3BSE008568R1: Modulebus Optical Port — fiber-optic inter-cluster link, TX/RX interface for noise-immune communication up to 80 m
• TB820 3BSE013208R1: Modulebus Optical Port, extended version with dual-port fiber connectivity for redundant cluster chaining
• TB840A 3BSE037760R1: Redundant Modulebus Optical Port — supports dual-path Modulebus for high-availability configurations
• TB845 3BSE021456R1: S800 I/O baseplate, 4-slot, compact form factor for space-constrained panel installations

Analog Input (AI) Modules

• AI810 3BSE008516R1: 8-channel analog input, 4–20 mA / 0–10 V, single-ended, 12-bit resolution
• AI820 3BSE008544R1: 8-channel analog input, differential, 16-bit resolution, HART pass-through capable
• AI830A 3BSE040662R1: 8-channel analog input, HART 5/6/7, 16-bit, loop-powered transmitter support
• AI893 3BSE050510R1: 16-channel analog input xSeries, HART 7, high-density, SIL 2 capable with AC800M HI

Analog Output (AO) Modules

• AO810 3BSE008522R1: 8-channel analog output, 4–20 mA, 12-bit, current sourcing
• AO820 3BSE008546R1: 8-channel analog output, 16-bit, HART pass-through, loop-powered
• AO890 3BSE045584R1: 8-channel analog output xSeries, HART 7, 16-bit, SIL 2 capable

Digital Input (DI) Modules

• DI810 3BSE008508R1: 16-channel digital input, 24 VDC, sink/source configurable
• DI820 3BSE008512R1: 16-channel digital input, 120 VAC, optically isolated
• DI890 3BSE045586R1: 32-channel digital input xSeries, 24 VDC, high-density, SIL 2 capable

Digital Output (DO) Modules

• DO810 3BSE008510R1: 16-channel digital output, 24 VDC, 0.5 A per channel, short-circuit protected
• DO820 3BSE008514R1: 8-channel relay output, 230 VAC / 30 VDC, SPDT contacts
• DO890 3BSE045588R1: 32-channel digital output xSeries, 24 VDC, high-density, SIL 2 capable

Communication & Interface Modules

• CI810B 3BSE020520R1: PROFIBUS DP master/slave adapter, connects S800 cluster to AC800M controller via PROFIBUS DP V1
• CI840A 3BSE041882R1: Redundant PROFIBUS DP adapter, dual-channel, supports hot-standby redundancy
• CI854A 3BSE030220R1: PROFIBUS DP / HART multiplexer interface, 16-channel HART device management

Sourcing Hard-to-Find & Obsolete S800 I/O Parts

A significant portion of the global S800 I/O installed base operates on modules that ABB has transitioned to limited availability or end-of-life status. First-generation baseplates (TB805, TB806), early AI810/DI810/DO810 variants, and copper-Modulebus communication adapters (CI810 original revision) are no longer in standard production. Replacement lead times through OEM channels can exceed 26 weeks.

DriveKNMS maintains a dedicated inventory of S800 I/O spare parts, including discontinued and hard-to-find module variants. Our sourcing network covers factory-surplus, decommissioned plant stock, and authorized secondary-market channels. All units are traceable to original manufacturer documentation. We support emergency procurement for unplanned outages, planned turnaround maintenance, and long-term lifecycle extension programs for plants operating beyond the original system design life.

Quality Control for the S800 I/O Range

S800 I/O modules present specific test challenges due to their backplane-dependent communication architecture and optical Modulebus interface. DriveKNMS applies the following verification procedures to all S800 I/O units prior to dispatch:

• Backplane continuity test: All TB-series baseplates are tested for inter-slot bus continuity and power rail integrity using dedicated S800 backplane test fixtures.
• Optical port verification (TB811 / TB820 / TB840A): Fiber TX/RX power levels are measured with an optical power meter. Minimum acceptable TX output: -15 dBm at 660 nm. Units outside specification are rejected.
• Functional I/O channel test: Each AI, AO, DI, and DO module is tested channel-by-channel under simulated load conditions. AI modules are verified for linearity across the full 4–20 mA range. DO modules are tested for switching response and short-circuit protection activation.
• HART communication test: HART-capable modules (AI830A, AI893, AO820, AO890, CI854A) are tested with a HART communicator to verify protocol handshake and device descriptor response.
• Firmware revision logging: Module firmware versions are recorded and disclosed to the customer prior to shipment to ensure compatibility with the target AC800M controller firmware baseline.