ABB 3bse036456r1 Ai825 Analog Input Module 4 CH

The ABB 3bse036456r1 (Ai825) is a high-density analog input module belonging to the S800 I/O family. It provides four isolated input channels for measuring current or voltage signals. Designed for process automation, this module supports HART communication pass-through, enabling seamless integration with smart transmitters. The module is compatible with AC 800M and other ABB controllers.

Input Specifications

Each channel individually configurable for: 0-20 mA, 4-20 mA, 0-10 V, ±10 V, or 2-10 V. Resolution: 16 bits (0.001% of full scale). Accuracy: ±0.1% at 25°C, ±0.2% over full temperature range. Input impedance: 250 Ω (current), >1 MΩ (voltage). Update time per channel: 10 ms for all channels simultaneously sampled.

HART Communication

The Ai825 supports HART pass-through on all four channels without additional hardware. It extracts HART digital signals superimposed on the analog current loop. HART commands can be sent via the fieldbus to configure or read diagnostic data from transmitters. The module is compliant with HART revision 5, 6, and 7.

Isolation and Protection

Each channel is galvanically isolated from the backplane and from other channels (500V AC). Overvoltage protection up to ±60V on current inputs and ±35V on voltage inputs. The module includes reverse polarity protection and current limit for loop supply. It also features a built-in loop diagnostic that detects open-circuit or short-circuit conditions.

Power and Environment

Backplane power: 5V DC (130 mA) and 24V DC (60 mA). Auxiliary power for loops: external 24V DC supply required (max 80mA per channel). Operating temperature: -40°C to +70°C (extended version). Humidity: 5% to 95% non-condensing. The module is hot-swappable and comes with a TU810 or TU812 termination unit (sold separately).

Fieldbus Integration

Communicates with the controller via the S800 I/O bus (Modulebus). Data is updated cyclically with configurable scan times. The module is configured using ABB’s Control Builder or 800xA system. It supports redundancy (dual modules) for high availability applications.

Diagnostics and Status

LED indicators: module health (green/red), each channel’s signal quality (yellow/green), HART activity (blinking green). The module logs over-range, under-range, and wire break events. A watchdog timer restarts the module in case of internal fault.

Applications

Typical in oil & gas, chemical, power generation, and water treatment plants. The Ai825 is used for reading pressure, temperature, flow, and level transmitters, especially those with HART capability.

Conclusion

The ABB 3bse036456r1 Ai825 analog input module offers four isolated channels with flexible signal selection and HART pass-through. Its accuracy, diagnostics, and redundancy support make it a reliable choice for process I/O applications.