ABB AC800M Modules: CI867K01 3BSE043660R1 Modbus TCP Interface

Technical Dossier

Product Details And Specifications

ABB AC800M Series Technical Notes

The ABB AC800M is a mid-to-high range Distributed Control System (DCS) controller platform deployed across global heavy industry sectors including petrochemical refineries, nuclear power generation facilities, pulp and paper mills, offshore oil and gas platforms, and large-scale chemical processing plants. Introduced in the early 2000s as the successor to the AC800C and Advant OCS lineage, the AC800M has accumulated an installed base spanning hundreds of thousands of control loops worldwide. Its modular backplane architecture, deterministic scan cycle, and native integration with ABB's System 800xA engineering environment make it the reference platform for process automation in facilities requiring IEC 61511 functional safety compliance and long-term vendor support commitments exceeding 20 years.

The CI867K01 (catalog number 3BSE043660R1) is the dedicated Modbus TCP/IP communication interface module for the AC800M controller family. It enables the AC800M CPU to communicate with third-party field devices, remote I/O stations, and SCADA systems over standard Ethernet infrastructure using the Modbus TCP protocol — the dominant open protocol in legacy and mixed-vendor automation environments.

The Evolution of AC800M Architecture

The AC800M platform was formally launched circa 2002, replacing the AC800C (Compact) and the earlier Advant Controller 450 (AC450) systems. The architecture is built around a proprietary CEX-Bus backplane that interconnects the CPU module, communication interface modules, and power supply units within a single rack. Early hardware revisions (PM851, PM856) supported single-processor configurations with limited memory. Subsequent generations introduced redundant CPU options (PM860, PM861, PM864, PM866) with expanded RAM, faster scan cycles, and support for the S800 I/O family over Modulebus optical fiber links.

Communication architecture evolved in parallel: early systems relied on PROFIBUS DP (CI854) and FOUNDATION Fieldbus H1 (CI871) as primary field protocols. The introduction of Industrial Ethernet-based modules — including the CI867 for Modbus TCP, CI873 for PROFINET IO, and CI874 for EtherNet/IP — reflected the industry transition toward unified plant networks. The CI867K01 specifically addresses integration scenarios where legacy Modbus RTU devices were migrated to Ethernet infrastructure without replacing end-field instruments.

As of 2024, ABB has transitioned the AC800M into a mature/sustained lifecycle phase. New greenfield projects are directed toward the ABB Ability System 800xA with AC800M High Integrity (AC800M HI) or the next-generation ABB Freelance 2000 platform. However, the installed base of AC800M systems in brownfield facilities ensures continued demand for spare modules, particularly communication interfaces and I/O modules, through at least 2035 under ABB's extended lifecycle support program.

AC800M Full Catalog & Functionalities (SKU List)

CPU / Controller Modules

• PM851K01 — 3BSE018168R1: AC800M base CPU, 32 MB RAM, single CEX-Bus slot, Modulebus master
• PM856K01 — 3BSE018100R1: AC800M standard CPU, 64 MB RAM, dual Ethernet ports, redundancy-capable
• PM860K01 — 3BSE018100R1: AC800M high-performance CPU, 128 MB RAM, extended I/O capacity
• PM861AK01 — 3BSE053240R1: AC800M CPU with integrated OPC DA server, 256 MB RAM
• PM864AK01 — 3BSE018161R1: AC800M high-capacity CPU, 512 MB RAM, redundant pair support
• PM866K01 — 3BSE050198R1: AC800M top-tier CPU, 1 GB RAM, fastest scan cycle in the family

Communication Interface Modules (CI Series)

• CI854AK01 — 3BSE030220R1: PROFIBUS DP master/slave interface, up to 125 nodes per segment
• CI857K01 — 3BSE018144R1: FOUNDATION Fieldbus HSE linking device interface
• CI858K01 — 3BSE018135R1: DeviceNet master interface, up to 64 nodes
• CI860K01 — 3BSE032444R1: FOUNDATION Fieldbus H1 interface, 2-segment support
• CI867K01 — 3BSE043660R1: Modbus TCP/IP client/server interface, 10/100 Mbps Ethernet, up to 64 simultaneous connections
• CI871K01 — 3BSE056767R1: FOUNDATION Fieldbus H1 interface, 4-segment, high-density variant
• CI873K01 — 3BSE056767R1: PROFINET IO controller interface, IRT and RT class support
• CI874K01 — 3BSE093555R1: EtherNet/IP adapter interface, CIP protocol, 100 Mbps
• CI875K01 — 3BSE021445R1: AF100 (Advant Fieldbus 100) interface for legacy Advant device migration

Digital Input / Output Modules (DI/DO)

• DI810 — 3BSE008508R1: 24 VDC digital input, 16 channels, S800 I/O family
• DI811 — 3BSE008552R1: 24 VDC digital input, 16 channels, NAMUR sensor compatible
• DO810 — 3BSE008510R1: 24 VDC digital output, 16 channels, 0.5 A per channel
• DO814 — 3BSE013258R1: 24 VDC digital output, 16 channels, 2 A per channel, high-current variant

Analog Input / Output Modules (AI/AO)

• AI810 — 3BSE008516R1: Analog input, 8 channels, 4–20 mA / 0–10 V, 12-bit resolution
• AI820 — 3BSE008544R1: Analog input, 8 channels, RTD/thermocouple, high-accuracy variant
• AO810V2 — 3BSE038415R1: Analog output, 8 channels, 4–20 mA, HART pass-through

Quality Control for the AC800M Range

AC800M modules present specific test challenges due to their CEX-Bus backplane communication protocol and proprietary firmware handshake sequences. DriveKNMS applies a multi-stage verification process for all AC800M inventory:

• Backplane continuity test: All CEX-Bus connector pins verified for impedance and signal integrity before module insertion.
• Firmware version verification: CPU and communication modules are booted in an isolated test rack running ABB Control Builder M to confirm firmware revision and license key validity.
• Protocol functional test: CI867K01 units are tested for active Modbus TCP client/server communication using a dedicated Modbus simulator, verifying all 64 connection slots and both read/write function codes (FC01–FC16).
• Burn-in cycle: All refurbished modules undergo a minimum 48-hour powered burn-in at rated operating temperature (0–55°C) to screen for early-life failures.
• Visual and mechanical inspection: Connector condition, PCB surface, and housing integrity inspected per IPC-A-610 Class 2 workmanship standards.