ABB Bailey INFI 90 Analog Terminal Cable Modules

Technical Dossier

Product Details And Specifications

ABB Bailey INFI 90 Series: Comprehensive Module Range and Technical Overview

The ABB Bailey INFI 90 (also marketed as Network 90) is a distributed control system (DCS) platform developed by Bailey Controls — later acquired by ABB — that achieved widespread deployment across heavy industrial sectors including petrochemical refineries, nuclear power stations, pulp and paper mills, and offshore oil and gas platforms. Installed base estimates place INFI 90 among the most extensively deployed DCS architectures of the 1980s–2000s era, with active installations still operating under long-term maintenance agreements globally. The system's modular backplane architecture, deterministic loop execution, and field-proven reliability made it the reference platform for continuous process control in facilities where unplanned downtime carries multi-million-dollar consequences.

The L700743A3-10 is an analog terminal cable assembly within the INFI 90 ecosystem, used to interface analog I/O modules with field termination assemblies (FTAs). It provides the physical signal path between the module backplane and the marshalling cabinet, maintaining signal integrity for 4–20 mA and millivolt-level process signals.

The Evolution of INFI 90 Architecture

The INFI 90 platform was introduced in the early 1980s as Bailey Controls' successor to the Network 90 system, sharing backward-compatible module form factors while introducing a higher-speed Nodebus communication backbone. The architecture is organized around the Plant Loop (INFI-NET), the Module Bus (Modulebus), and individual I/O modules seated in IMMFP/IMFEC controller-based racks.

Key architectural generations:

• Network 90 (pre-INFI 90): Original Bailey DCS; limited to 4,096 I/O points per system. Many Network 90 modules share physical form factors with early INFI 90 hardware, creating cross-compatibility considerations during upgrades.
• INFI 90 Open (1990s): Introduced open connectivity via OPC and Ethernet gateways. The IMMFP12 and IMFEC08 controllers became the dominant CPU modules of this era.
• Symphony Plus (2000s–present): ABB's current-generation successor platform. Symphony Plus is not backward-compatible at the module level with INFI 90 I/O hardware, making original INFI 90 spare parts irreplaceable for sites that have not undergone full migration.

Sites running INFI 90 that have not migrated to Symphony Plus face a structural spare parts challenge: ABB ceased manufacturing most INFI 90 modules, and the installed base depends entirely on the secondary market and specialist distributors for lifecycle extension.

INFI 90 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced modules within the ABB Bailey INFI 90 / Network 90 platform. Each entry reflects a distinct functional role within the system architecture.

Controllers & Processors

• IMMFP12: Multi-Function Processor; primary CPU module for INFI 90 control stations, executes function code blocks.
• IMFEC08: Field Equipment Controller; manages I/O scanning and loop execution for distributed I/O racks.
• IMDSO14: Distributed Single-Loop Controller; standalone PID loop execution with local operator interface.
• IMCPM02: Control Processor Module; earlier-generation CPU used in Network 90 and early INFI 90 racks.

Analog Input / Output Modules

• IMDSI02: Digital Input Module; 16-channel 24 VDC discrete input, used for contact closure monitoring.
• IMDSO02: Digital Output Module; 16-channel relay output for solenoid and motor starter control.
• IMASI02: Analog Signal Input Module; 8-channel 4–20 mA / 1–5 VDC input with signal conditioning.
• IMASO01: Analog Signal Output Module; 4-channel 4–20 mA output for control valve positioners.
• IMAII01: Analog Input Isolator Module; provides galvanic isolation for field analog signals.
• IMAIO01: Analog I/O Module; combined analog input/output for compact loop configurations.

Communication & Network Modules

• INICT03: INFI-NET Communication Interface; connects control stations to the Plant Loop fiber-optic network.
• IMCIS02: Communication Interface Slave; provides Modulebus-to-host computer data exchange.
• IMLAN01: Local Area Network Interface; Ethernet gateway for INFI 90 to supervisory systems.

Power Supply Modules

• IMPS02: Power Supply Module; 24 VDC rack power supply for INFI 90 I/O racks, redundant-capable.
• IMPS10: Enhanced Power Supply; higher-current variant for fully populated 19-slot racks.

Cable & Termination Assemblies

• L700743A3-10: Analog Terminal Cable; 10-conductor shielded cable assembly connecting analog I/O modules to field termination assemblies (FTAs).
• NTAI05: Analog Input Termination Unit; FTA for IMASI02 analog input modules, screw-terminal field wiring interface.
• NTAO01: Analog Output Termination Unit; FTA for IMASO01 analog output modules.

Sourcing Hard-to-Find & Obsolete INFI 90 Parts

ABB formally transitioned its DCS product line to Symphony Plus, and the majority of INFI 90 module manufacturing has been discontinued. For plant operators maintaining INFI 90 systems under long-term service agreements or deferring migration, the secondary market is the only viable source for replacement modules, cable assemblies, and termination hardware.

DriveKNMS maintains a dedicated inventory of verified INFI 90 spare parts, including hard-to-find CPU modules, I/O cards, communication interfaces, and cable assemblies such as the L700743A3-10. Our sourcing network covers decommissioned plant stock, authorized surplus, and tested pull-outs from controlled environments. All units are cataloged by part number, revision level, and functional test status prior to listing.

For end-of-life module support, DriveKNMS provides: part number cross-referencing across INFI 90 and Network 90 generations, revision-level compatibility verification, and bulk procurement for scheduled maintenance shutdowns.

Quality Control for the INFI 90 Range

INFI 90 modules present specific test challenges due to their proprietary Modulebus backplane protocol and multi-layer PCB construction. DriveKNMS applies the following verification procedures to all INFI 90 inventory:

• Visual inspection: Component-level examination for capacitor degradation, relay contact wear, and PCB trace corrosion — failure modes common in modules with 20+ years of service.
• Backplane communication test: Each controller and I/O module is seated in a live INFI 90 test rack and verified for Modulebus enumeration and data exchange.
• Analog signal calibration: Analog input and output modules are tested across the full 4–20 mA range using calibrated signal sources and loads, with linearity and offset measurements recorded.
• Cable assembly continuity: Terminal cable assemblies including the L700743A3-10 are tested conductor-by-conductor for continuity, insulation resistance, and shield integrity.
• Firmware revision logging: Where applicable, firmware version is recorded and disclosed to the buyer prior to shipment.