Application Scenarios:

In a thermal power plant’s boiler control system, the ABB SPASI23​ module is deployed to monitor combustion efficiency and safety. It simultaneously connects to Type K thermocouples​ measuring furnace gas temperatures (up to 1300°C), 4-20 mA pressure transmitters​ monitoring steam headers, and Pt100 RTDs​ tracking bearing temperatures on induced draft fans. The module’s individual channel configuration allows the DCS to precisely acquire all these disparate signals in a single rack slot. Its high common-mode rejection (≥120 dB) filters out electrical noise from nearby high-voltage motors, ensuring the control system receives clean data to regulate fuel-air ratios and prevent boiler overheating.

 

Parameter:

Main Parameters	Value/Description
Product Model​	ABB SPASI23​
Manufacturer​	ABB
Product Type​	16-Channel Universal Analog Input Module (AI)
Compatible System​	Symphony Plus, Harmony, Infi 90 DCS
Input Channels​	16 channels​ (individually configurable)
Supported Signals​	TC​ (J/K/T/E/R/S/B/N), mV​ (±100 mV), RTD​ (Pt100, Pt1000, Cu10, Cu50), High-Level​ (4-20 mA, 0-10 V, ±10 V)
A/D Resolution​	16-bit​ (effective, ±0.05% to ±0.1% FSR accuracy)
Sampling Rate​	100 Hz​ (per channel, typical)
Isolation Voltage​	1500 V AC / 2500 V RMS​ (channel-to-backplane/field)
Supply Voltage​	24 V DC​ (via backplane or terminal)
Power Consumption​	~2.5 W – 5 W (typical)
Operating Temperature​	-20°C to +60°C​ (industrial grade)
Mounting​	DCS Rack / DIN Rail (via mounting unit)
Dimensions (Module)​	Approx. 120 x 80 x 35 mm​ (varies by carrier)

 

 

Technical Principles and Innovative Values:

The ABB SPASI23​ addresses the critical challenge of high-density, mixed-signal acquisition in electrically hostile environments, offering significant advancements over standard AI modules.

• Innovation Point 1: True Universal Channel Flexibility.​ Unlike fixed-function modules, each of the SPASI23’s 16 channels is software-configurable per channel. This allows a single module to replace multiple dedicated boards (e.g., one for TC, one for RTD, one for 4-20 mA), drastically reducing spare part inventory and cabinet space. Engineers can dynamically assign signal types via the DCS configuration without hardware changes.
• Innovation Point 2: High-Noise Immunity for Low-Level Signals.​ The module is engineered with sigma-delta ADC technology​ and ≥120 dB common-mode rejection​ at 50/60 Hz. This is critical for accurately measuring microvolt-level thermocouple signals in environments saturated with EMI from VFDs and large motors, preventing signal corruption that could lead to false tripping or control instability.
• Innovation Point 3: Seamless Integration with Legacy and Modern DCS.​ The SPASI23 is designed for backward compatibility with Bailey Infi 90​ systems while fully supporting the Symphony Plus​ architecture. This dual compatibility provides a smooth migration path for legacy plant upgrades, protecting existing investments while enabling modern data acquisition capabilities.

 

Application Cases and Industry Value:

Case: Petrochemical Plant Reactor Temperature Monitoring Upgrade.A petrochemical facility’s batch reactor was experiencing inconsistent product quality due to unreliable temperature readings from its aging 8-channel AI modules. The legacy setup required separate modules for RTDs and TCs, complicating wiring and maintenance. The system was upgraded with ABB SPASI23​ modules. Each module was configured with 8 channels for reactor wall RTDs and 8 channels for catalyst bed TCs. The high channel density halved the required rack space. The module’s built-in linearization and cold junction compensation for TCs delivered accuracy within ±0.1°C, enabling precise control of the exothermic reaction. This resulted in a 15% improvement in batch consistency​ and a significant reduction in sensor-related I/O card failures.