ABB INFI-Net Modules: SPIET800 IET800

Technical Dossier

Product Details And Specifications

ABB INFI-Net Series: Comprehensive Module Range and Technical Overview

The ABB INFI-Net (Intelligent Network Interface) platform is a core communication backbone within ABB's Network 90 and Harmony DCS architecture. Deployed extensively across global heavy industry — including petrochemical refineries, nuclear power stations, pulp and paper mills, and offshore oil platforms — INFI-Net modules provide deterministic, high-speed token-passing network communication between controllers, I/O subsystems, and operator workstations. The installed base of INFI-Net hardware spans several decades of continuous operation, making lifecycle support and spare parts availability a critical operational requirement for plant engineers and maintenance teams worldwide.

The Evolution of INFI-Net Architecture

ABB's INFI-Net architecture was introduced as part of the Network 90 DCS platform in the early 1980s, designed to replace proprietary point-to-point wiring with a structured, coaxial-based token bus network operating at 1 Mbps. The original INFI-Net used a dual-redundant coaxial cable topology, with modules such as the INICT03 and INICT13 serving as network interface controllers embedded within the Multi-Function Controller (MFC) and Process Interface Unit (PIU) chassis.

Through the 1990s, ABB extended INFI-Net compatibility into the Harmony series, introducing fiber-optic repeaters and bridge modules to extend network reach across large plant footprints. The SPIET800 IET800 represents a critical evolution point: a dedicated INFI-Net to Ethernet gateway that allows legacy Network 90 / Harmony nodes to communicate with modern Ethernet-based supervisory systems, historians, and OPC servers — without requiring a full DCS migration. This module is essential for plants operating in a hybrid legacy-modern environment, bridging a 1980s token bus architecture with contemporary TCP/IP infrastructure.

As of 2026, the INFI-Net platform is in its end-of-life and mature support phase. ABB has transitioned its DCS portfolio to the System 800xA platform. However, the installed base remains active at thousands of sites globally, and replacement modules are no longer manufactured in volume, making certified refurbished and new-old-stock (NOS) units the primary sourcing channel.

INFI-Net Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced modules within the ABB INFI-Net / Network 90 / Harmony DCS ecosystem. Each entry reflects a distinct functional role within the system architecture.

SPIET800 / IET800: INFI-Net to Ethernet Transfer Module; bridges legacy token bus to TCP/IP networks.
INICT03: INFI-Net Interface Controller; primary network interface for MFC chassis slots.
INICT13: INFI-Net Interface Controller (enhanced); supports extended node addressing on large networks.
INNIS21: INFI-Net Interface Module; used in PIU and slave controller configurations.
INNIS31: INFI-Net Interface Module (redundant); dual-port configuration for fault-tolerant topologies.
INRPG01: INFI-Net Repeater Module; extends coaxial segment length and regenerates signal integrity.
INRPG11: INFI-Net Fiber Optic Repeater; converts coaxial INFI-Net to fiber for long-distance or electrically noisy runs.
INBRI01: INFI-Net Bridge Module; connects two independent INFI-Net segments for large plant architectures.
INMFC01: Multi-Function Controller; primary process controller node on the INFI-Net backbone.
INMFC11: Multi-Function Controller (enhanced memory); supports larger control strategy databases.
INPCT01: Process Control Terminal Interface; operator interface node on INFI-Net.
INPCT11: Process Control Terminal Interface (enhanced); supports additional display nodes.
INPIU01: Process Interface Unit; I/O expansion chassis interfacing to INFI-Net via INNIS modules.
INPIU21: Process Interface Unit (extended); supports higher-density I/O configurations.
INAI16: 16-Channel Analog Input Module; 4–20 mA process signal acquisition for PIU chassis.
INAO08: 8-Channel Analog Output Module; 4–20 mA control output for final control elements.
INDI16: 16-Channel Digital Input Module; 24 VDC discrete signal acquisition.
INDO16: 16-Channel Digital Output Module; 24 VDC relay-driven discrete outputs.
INRTM01: RTD/Thermocouple Input Module; direct temperature sensor interface for process measurement.

Sourcing Hard-to-Find & Obsolete INFI-Net Parts

DriveKNMS maintains a dedicated inventory program for ABB INFI-Net and Network 90 / Harmony platform components. As ABB has formally discontinued volume production of INFI-Net modules, the global supply chain for these parts is limited to authorized refurbishers, surplus dealers, and new-old-stock repositories.

DriveKNMS sources SPIET800 IET800 units and the full INFI-Net module catalog through a verified global supplier network. All units are inspected, tested, and documented prior to shipment. For plants requiring long-term maintenance agreements or multi-year spare parts reservations, DriveKNMS offers consignment stocking and priority allocation programs. This is particularly relevant for facilities with regulatory constraints — such as nuclear or chemical plants — where DCS migration is not operationally feasible within a standard maintenance window.

Customers are encouraged to submit their full bill-of-materials (BOM) for cross-referencing against current stock. Emergency same-day quotation is available for critical plant shutdowns.

Quality Control for the INFI-Net Range

ABB INFI-Net modules — particularly communication-layer components such as the SPIET800 IET800, INICT03, and INNIS series — require specialized test procedures that replicate the token-passing bus environment of a live Network 90 system. Standard bench testing is insufficient for validating network interface functionality.

DriveKNMS employs the following quality control protocol for INFI-Net modules:

• Visual inspection of backplane connectors, EPROM sockets, and capacitor arrays for physical degradation.
• Powered functional test using a dedicated INFI-Net test rig that simulates a live token bus segment with at least two active nodes.
For gateway modules (SPIET800 / IET800): end-to-end Ethernet packet transmission test with OPC DA/UA data validation.
• Firmware version verification against ABB's published revision history to ensure compatibility with target system software releases.
• Burn-in cycle: 48-hour continuous operation under simulated load prior to shipment.
• Final documentation package: test report, firmware version, physical condition grade, and warranty certificate.