The ABB DI651 (3BHT300026R1) is a robust, high-density digital input module designed for the ABB Advant Controller 410/450 series, widely deployed in complex industrial automation and control systems. Built to collect and process digital signals in critical applications, the DI651 offers a reliable interface between field devices and ABB’s distributed control system (DCS).

Equipped with 64 digital inputs, this module significantly reduces cabinet space and wiring requirements by doubling the channel count in a single housing, making it a practical choice for large-scale installations. The DI651 is engineered with opto-isolated channels, ensuring high immunity against electromagnetic interference and electrical surges, while offering accurate, real-time signal detection.

Its compact design, excellent electrical protection, and seamless integration with legacy and current ABB control architectures make it a staple in industrial settings such as energy generation, refining, chemical manufacturing, metals, and utilities.

Technical Specifications

Applications

• Power Plants (Fossil, Nuclear, Renewable)

  Monitors critical equipment states like valve positions, circuit breakers, and safety interlocks.

• Oil & Gas Facilities

  Handles digital feedback from process instruments, alarm contacts, emergency shutdown systems (ESD), and valve limit switches.

• Chemical Processing Units

  Interfaces with digital signals from safety relays, interlocks, and sequencing controls in batch or continuous processes.

• Pulp & Paper Mills

  Collects input from conveyor switches, motor starters, and limit sensors throughout production lines.

• Mining and Metallurgy Plants

  Used for heavy-duty contact inputs in rugged environments, including crushers, grinders, and safety gate monitoring.

• Industrial Automation Systems

  Supports high-speed input scanning for real-time control of machinery, robotics, and conveyance systems.

• Water Treatment and Wastewater Facilities

  Reads pump and valve statuses, overflow conditions, and contact closure signals for control room feedback.

Key Advantages

• Ultra-High Channel Density

  64 digital inputs in a compact footprint significantly lower rack space and wiring complexity.

• Proven in Mission-Critical Systems

  Trusted in global industries with long service life and consistent field reliability.

• Comprehensive Diagnostics

  Built-in group diagnostics simplify troubleshooting and preventive maintenance.

• Flexible System Integration

  Works seamlessly with ABB’s Advant and Symphony platforms—ideal for both upgrades and greenfield installations.

• Reduced Downtime

  Field-replaceable without disrupting system-wide operations; supports hot-swapping in some configurations.

• Enhanced Electrical Protection

  Opto-isolation and protective circuitry prevent damage from voltage surges and transients.

• Lifecycle Support & Spare Availability

  ABB offers extended support programs and long-term availability of spares and replacements.

Frequently Asked Questions (FAQ)

1. What is the maximum number of DI651 modules that can be installed in one controller rack?

   It depends on system load and power budget; typically 4–6 per rack with spacing considerations.

2. Does DI651 support individual channel diagnostics?

   No, diagnostics are grouped. Individual channel diagnostics are not available on this model.

3. Is hot-swapping possible with the DI651 module?

   Only in systems configured for redundancy and hot-swap support. Most installations require a safe stop.

4. What kind of field signals can the module detect?

   Any dry contact or active 24 VDC signal from limit switches, relays, sensors, etc.

5. How is the wiring done for 64 channels?

   Wiring is managed via terminal base units, often segmented into groups for cable organization.

6. Is the DI651 supported in ABB’s current configuration tools?

   Yes, supported via legacy Advant tools and partially in Symphony Plus engineering environment.

7. Can it be used with third-party PLCs?

   Not directly. DI651 is tailored for ABB’s proprietary bus and system architecture.

8. How is LED indication implemented?

   Status LEDs are available per input group, not per channel.

9. What happens in case of a module fault?

   The system will trigger an alarm; group diagnostics and hot standby modules (if configured) handle failover.

10. Is there any compatibility between DI651 and S800 I/O systems?

    No. DI651 is part of the Advant DCS line, while S800 is a separate modular I/O system.