ABB DP840 3BSE028926R1 Pulse counter

The DP840 is a high-performance, multi-channel pulse counting and frequency (speed) measurement module in the ABB System 800xA® series. This module features 8 independent channels, each configurable for pulse counting or frequency measurement, supporting input frequencies up to 20 kHz. The DP840 interfaces with NAMUR, 12V, and 24V sensor signals and comes with comprehensive diagnostic functions and redundancy capabilities, making it suitable for industrial automation applications requiring high signal acquisition reliability.

Designed with a compact form factor, the module is compatible with various Module Termination Units (MTUs) and can be integrated into the S800 I/O system. It is ideal for signal acquisition and control tasks in process industries, manufacturing, energy management, and other fields.

2. Detailed Features

1. Independent Multi-Channel Configuration

The DP840 provides 8 completely independent channels, each configurable based on application needs:

• Pulse Counting Mode: Accurate counting via a 16-bit accumulation counter.

• Frequency (Speed) Measurement Mode: Calculates actual frequency based on a reference frequency and pulse count.

• Digital Input (DI) Mode: Direct reading of digital signals.

2. Flexible Sensor Interface

Each channel supports three sensor signal types:

• NAMUR sensors (intrinsically safe signals).

• 12 V sensors.

• 24 V sensors.

The module can uniformly configure the sensor power supply type (NAMUR/12V/24V) for all channels and includes power monitoring and current limiting protection.

3. High-Precision Measurement and Filtering

• Frequency measurement is based on a dual-counter (SX and SR) structure, calculated using the formula:

  Fx=FREF×SxSrFx=FREF×SrSx

  where FREFFREF is the reference frequency, SxSx is the input pulse count, and SrSr is the reference pulse count.

• Users can set the measurement cycle (10 ms, 20 ms, 50 ms, 100 ms) to balance response speed and noise suppression.

• Configurable input filter times (10 µs – 6400 µs) suit signals of different frequency ranges.

4. Comprehensive Diagnostic Capabilities

The DP840 features multi-level diagnostics:

• Module-Level Diagnostics: Includes data/address bus errors, synchronization errors, etc., indicated by module LEDs (F, R, W, P).

• Channel-Level Diagnostics: Each channel has two LEDs (Px yellow indicates pulse activity, F red indicates channel fault).

• Sensor Loop Monitoring: Supports short circuit and open wire detection, can be enabled/disabled.

• Power Supply Monitoring: Both sensor power and process power supplies are monitored.

5. Redundancy Configuration Support

The DP840 can operate as a primary or backup module in redundant systems. The primary module synchronizes the backup module's counters every 10 seconds, with synchronization completing approximately 30 seconds after startup, ensuring high system availability.

6. Compatibility and Expandability

The module is compatible with various Module Termination Units (MTUs), accommodating different wiring methods and signal types. All compatible MTUs use the same keying code (CF) to prevent incorrect insertion.

3. Application Areas

The DP840 is suitable for the following industrial scenarios:

• Process Industries: Signal acquisition from flow meters, encoders, speed sensors.

• Manufacturing and Machinery: Production line speed monitoring, equipment operation counting.

• Energy Management: Electrical pulse counting, frequency monitoring.

• Safety Systems: Used in control loops requiring high reliability under redundant configurations.

• Marine and Offshore Platforms: Compliant with marine certifications, suitable for harsh environments.

  
  

4. Compatibility and Connection Information

1. Compatible MTU List

2. Wiring Examples

• TU810 / TU814: Suitable for terminal block wiring, supports all sensor types.

• TU812: Uses a D-Sub 25-pin connector, suitable for compact installations.

• TU830 / TU833: Supports wiring with short circuit and open wire detection.

• TU842 / TU843, TU844 / TU845, TU852 / TU854: Designed for redundant systems, providing dual power inputs and signal isolation.

For detailed wiring diagrams and terminal assignments, refer to the figures in the product manual (Figures 205–209).

5. Detailed Technical Parameters

1. Electrical Characteristics

• Input Impedance:

• NAMUR: 1 kΩ ±10%

• 12 V: 2.8 kΩ ±10%

• 24 V: 4.0 kΩ ±10%

• Sensor Power Supply:

• NAMUR: 8.2 V ±10%, max. 20 mA per channel

• 12 V: 12 V ±10%

• 24 V: VL+−(3.0±1.0) VVL+−(3.0±1.0)V

• Current Consumption:

• NAMUR: 56 mA + 0.5 × sensor current

• 12 V: 89 mA + 0.7 × sensor current

• 24 V: 97 mA + sensor current

• +5 V (ModuleBus): 115 mA

• +24 V (External Power Supply):

2. Environmental and Certifications

• Operating Temperature: 0 to +55 °C (40 °C when vertically mounted in compact MTU)

• Storage Temperature: -40 to +70 °C

• Relative Humidity: 5–95% (non-condensing)

• Pollution Degree: Degree 2 (IEC 60664-1)

• Protection Class: IP20 (IEC 60529)

• Certifications: CE, UL, ATEX Zone 2, cULus, BV/DNV/LR (Marine), RoHS (EU, UAE, China), WEEE, etc.

3. Mechanical Dimensions

• Width: 45 mm

• Depth: 102 mm (excluding connector), 111 mm (including connector)

• Height: 119 mm

• Weight: 0.15 kg