Description

Product Overview

The IMDSI02 is an ABB Bailey INFI 90 Digital Slave Input module used to bring discrete field signals into the INFI 90 Process Management System for monitoring and processing. It provides 16 independent digital input channels and is suitable for signals originating from contacts, switches, solenoid devices, and similar field equipment. The module communicates with a master module through the slave expander bus, while field wiring is connected through the associated termination unit or termination module. The documented input ranges include 24 VDC, 125 VDC, and 120 VAC.

This architecture makes the IMDSI02 useful for maintaining legacy INFI 90 DCS installations where reliable discrete signal acquisition remains necessary. Personally, I would verify the termination-unit configuration and input-voltage selection before replacement, because the field-side setup is just as important as the module itself.

Technical Specifications — IMDSI02

The module uses front-panel LED indicators to display individual input status. The documented DC response can be configured for fast or slow operation, with typical response times of 1.5 ms and 17 ms respectively.

ABB IMDSI02

Key Features and Benefits — IMDSI02

• 16-channel discrete input architecture for INFI 90 systems.
• Accepts 24 VDC, 125 VDC, and 120 VAC field inputs.
• Supports process monitoring through the INFI 90 slave expander bus.
• Front-panel LEDs provide direct indication of input status.
• Uses optical isolation within the input circuitry.
• Suitable for contact, switch, and solenoid-related field signals.
• Designed for one-slot installation in a standard INFI 90 Module Mounting Unit.
• Field connections are made through compatible termination hardware.

The input circuits use threshold detection and optocouplers, while termination-unit jumpers determine the applicable input configuration. This means the replacement should be matched with the existing termination arrangement rather than installed solely by module number.

Related Models

IMDSO01 — An INFI 90 digital output module for switching external loads across specified AC and DC voltage ranges.

IMDSO02 — A digital output module designed around 24 VDC applications, providing eight discrete outputs.

IMDSM04 — A pulse-input module used for pulse and frequency-type process signals rather than conventional discrete inputs.

IMASO01 — An analog output module supporting 1–5 VDC and 4–20 mA signal applications.

Installation and Maintenance — IMDSI02

Before installation, isolate the relevant DCS equipment according to site electrical-safety procedures. Verify the module identification, slot position, termination unit, field-voltage configuration, and master-module addressing.

The associated NTDI01 termination unit uses configurable dipshunts for the digital inputs. Incorrect configuration can result in missing signals or improper input detection, so the existing settings should be recorded before removing the original module.

Inspect the board, edge connectors, captive screws, and status LEDs for physical damage or contamination. Use ESD precautions when handling the circuit board. After installation, test each relevant input point and confirm correct status indication and DCS point processing before returning the control loop to normal operation.

Product Warranty — IMDSI02

Warranty coverage depends on the supplier and supplied condition. Before purchasing, confirm whether the module is new, unused surplus, refurbished, or previously installed, and request available inspection or functional-test records.

For critical INFI 90 spare inventory, retain the complete model number, serial number where applicable, inspection status, storage history, and termination configuration records. This improves traceability and reduces avoidable errors during future DCS maintenance.