ABB S800 I/O 3BSE020838R1 DO840 Digital Output Module

S800 I/O Digital Output Module Overview

The 3BSE020838R1 (DO840) is a high-reliability digital output module within ABB’s S800 I/O system, designed for industrial automation and process control applications. It provides 16 channel 24V DC transistor outputs with advanced diagnostics and flexible redundancy options.

The module is engineered for demanding control environments where stable switching performance, channel isolation, and system diagnostics are critical. It is widely used in ABB 800xA and Compact Product Suite architectures to drive actuators, solenoids, and interlocking systems in continuous industrial operations.

System Architecture & Function Design

The DO840 is designed with a focus on channel isolation, modular redundancy, and diagnostic transparency:

• Channel Configuration: 16 digital outputs divided into 2 isolated groups of 8 channels.
• Redundancy Support: Supports both single and redundant system configurations for high availability applications.
• Output Rating: 0.5A per channel for reliable switching of field devices.
• On-board Diagnostics: Advanced diagnostics enable real-time fault detection and channel-level monitoring.
• Module Integration: Designed for S800 I/O racks and compatible with ABB 800xA and Compact Product Suite systems.

Electrical & Mechanical Data

Application & Operational Notes

Can the DO840 operate in redundant configurations?

Yes. The module supports redundant setup when used with compatible S800 I/O system architecture, ensuring high system availability in critical process control applications.

What type of loads can the outputs drive?

Each channel supports 24V DC loads up to 0.5A, typically used for solenoids, relays, indicators, and small actuator devices in automation systems.

How is diagnostic information provided?

The module includes advanced on-board diagnostics that report channel faults, communication status, and power supply conditions directly to the control system.

Installation & Engineering Guidelines

MTU Compatibility:
The DO840 must be installed with compatible Module Termination Units (TU810, TU812, TU814, TU830, TU833, TU842, TU843, TU852). Proper MTU selection ensures correct wiring density and system reliability.

Wiring Isolation:
The outputs are divided into two isolated groups. Maintain proper separation to avoid cross-coupling and ensure signal integrity in high-density cabinets.

Thermal Management:
Although the module has low power dissipation, ensure proper cabinet ventilation when multiple I/O modules are installed in close proximity.

System Integration:
When used in 800xA systems, ensure correct I/O configuration in controller software to enable full diagnostic and redundancy features.