Description

ABB IMASI23 Multifunction 16-Channel Analog Input Module

Technical Specifications

• Product Model: IMASI23
• Brand: ABB
• Warranty: One Year
• Input Voltage: 24 VDC ±10% rack backplane power, 5VDC internal auxiliary power
• Operating Temperature: -25°C to +60°C
• Storage Temperature: -40°C to +85°C
• Response Time: Total 16-channel full scanning cycle 180ms, independent per-channel 24-bit A/D conversion
• Protection Class: IP20, Harmony/Symphony Plus rack mounted cabinet installation
• Accuracy Class: ±0.02% full scale conversion accuracy, maximum temperature drift ±0.003% FS/°C
• Output Frequency: Internal module sampling clock 5kHz
• Rated Current Range: Total power consumption ≤5W, maximum 0.21A at 24VDC
• Communication Interface: ABB proprietary Symphony Harmony I/O Expander backplane bus
• Supported Protocols: Symphony Plus DCS internal rack bus, cold junction compensation proprietary algorithm
• Overload Capacity: Per-channel galvanic isolation (500VAC dielectric withstand), overvoltage clamping, open/short circuit loop detection, EMC surge suppression
• Dimensions: 229mm (L) × 51mm (W) × 330mm (H), standard ABB Harmony single slot rack form factor
• 

Product Overview

The IMASI23 is a high-density, multi-type universal analog input I/O card designed exclusively for ABB Symphony Plus and Harmony distributed control systems deployed in power generation, petrochemical, pulp and paper, and heavy industrial process plants. This rack-based module integrates 16 fully independent input channels, each equipped with a dedicated 24-bit analog-to-digital converter to acquire diversified field process signals including thermocouples, 3-wire RTDs, millivolt signals, 4–20mA loop current, and bipolar/ unipolar DC voltage transmitters. It builds in automatic cold junction compensation for thermocouple measurements and on-board continuous channel integrity diagnostics to deliver calibrated, reliable digital data to the DCS main controller for closed-loop regulation, equipment protection and historical trending.

It addresses core measurement drawbacks in large-scale process control environments, including inconsistent conversion precision from shared multi-channel ADC chips, cross-channel signal crosstalk without individual isolation, inaccurate thermocouple readings caused by missing cold junction compensation, limited signal type compatibility on single-function AI modules, and lengthy downtime during spare module replacement. Constructed with channel-by-channel DC/DC isolation circuits, noise filtering hardware, non-volatile memory for parameter retention and front-panel fault indicator LEDs, the module maintains stable measurement performance under cabinet temperature cycling, plant vibration, and electromagnetic interference from high-voltage switchgear and rotating equipment.