ABB 07AI91 Analog Input Module for CS31 System Bus

Product Overview

Designed as a remote module for the CS31 system bus, this unit offers 8 analog input channels that you can configure in pairs for various sensor types. As a maintenance engineer, you will appreciate its straightforward setup and robust diagnostics.

Technical Specifications Breakdown

The 07AI91 operates on a rated supply voltage of 24 V DC, with a maximum current consumption of 0.15 A and maximum power dissipation of 3 W. Protection against reversed polarity of the power connection is built in, reducing the risk of damage during installation. The module supports line frequency suppression configurable for 50 Hz, 60 Hz, or none, with a software filter of 20.0 ms at 50-Hz suppression and 16.7 ms at 60-Hz suppression. Permissible input overvoltage is max. +/- 30 V, and the input delay is 0 (no RC combination). These specs ensure stable readings in industrial environments.

Industry Applications

In process plants, the 07AI91 is used for monitoring temperatures from Pt100 or thermocouple sensors (types J, K, S) with linearization. For example, you can connect type J (Fe-CuNi) thermocouples for furnace monitoring up to 1200 °C. The module also handles voltage inputs (±10 V, ±5 V, ±500 mV, ±50 mV) and current inputs (0...20 mA or 4...20 mA with an external 250 Ω resistor). This flexibility makes it suitable for both temperature and signal conditioning tasks.

Installation & Setup Guidance

Mount the 07AI91 on a DIN rail (15 mm high) or use 4 screws (M4). Wiring uses removable terminal blocks with screw-type terminals, accepting conductor cross sections up to max. 2.5 mm². Configure input channels and module address using the DIL switches (coding switch under the right housing cover). Remember: only electrically isolated sensors may be used. For unused channels, bridge the input terminals to maintain proper operation.

Maintenance & Reliability

From a maintenance perspective, the 07AI91 offers self-calibration and diagnosis functions for all channels. The front panel provides 17 LEDs for channel selection, analog value display, and error messages, making troubleshooting quick. The permissible temperature range during operation is 0...55 °C, so ensure adequate ventilation in cabinets. No special cleaning procedures are required; periodic inspection of connections and LED status is sufficient.

Compatibility & Integration

The 07AI91 communicates via the CS31 system bus, which is electrically isolated from the rest of the unit. It uses one module address (group number) in the word input range, with each of the 8 channels using 16 bits. This integration is straightforward with ABB CS31-compatible controllers. The module is powered by 24 V DC, and the bus connection is isolated for noise immunity.