Description
System Role and Integration
The 1C31147G01 serves as the pulse counting interface within the Ovation Distributed Control System architecture, functioning as the critical measurement element for applications requiring accurate accumulation of discrete pulses from field devices. As a Pulse Input Electronics Module (EMOD), it mounts in standard Ovation I/O bases and operates in conjunction with the 1C31150 series Personality Modules (PMODs) to create a complete pulse counting solution for flow computers, turbine meters, and rotary encoders.
This module occupies a specialized position in process measurement applications where volumetric flow rates, rotational speeds, or linear displacements are determined by counting pulses generated by mechanical or electronic sensors. Unlike analog input modules that measure continuous voltage or current signals, the 1C31147G01 processes discrete pulse trains, converting the frequency and count of incoming pulses into digital values for totalization and rate calculation algorithms within the Ovation controller.
Core Functionality and Signal Handling
The module provides two independent pulse input channels configured for medium-speed operation, accepting pulse signals at 5/12VDC or 24/48VDC levels depending on the installed Personality Module configuration. Each channel features a 32-bit counter capable of accumulating pulse counts without rollover for extended periods, ensuring accurate totalization even during high-flow conditions or long-duration batch cycles.
Signal conditioning circuitry includes programmable filtering and debounce capabilities to eliminate electrical noise and contact bounce from mechanical switch inputs, ensuring that only valid pulses are counted. The module interfaces with the Ovation controller via the LocalBus or Standard Bus (depending on chassis configuration), transferring count values and status information to the control processor for real-time rate calculations and historical data logging.
The 1C31147G01 requires specific Personality Modules (1C31150G01, G02, or G03) to configure the input voltage range and field power supply characteristics. These PMODs provide the necessary termination resistors, voltage dividers, and field power distribution to match the specific pulse output characteristics of turbine flow meters, positive displacement meters, or encoder devices.
Platform Heritage and Operational Benefits
As a component of the Westinghouse Ovation platform now maintained within Emerson’s automation portfolio, the 1C31147G01 reflects the precision measurement capabilities required for custody transfer metering, process flow monitoring, and machinery speed control. The module’s ±0.1% accuracy specification ensures compliance with industry standards for flow measurement uncertainty, while the 32-bit counter depth eliminates the need for frequent controller reads to prevent count rollover during extended operational periods.
The modular EMOD/PMOD architecture allows the same electronics module to serve diverse pulse input applications through appropriate personality module selection. The 1C31147G01 handles the high-speed counting and signal conditioning, while the PMOD provides the voltage-specific interface and field wiring termination. This separation reduces spare parts inventory requirements—facilities stock the universal EMOD and specific PMODs for their installed sensor base rather than maintaining complete dedicated pulse input cards for each voltage range.
WESTINGHOUSE 1C31147G01
Part 4: Technical Specifications
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Model Number: 1C31147G01
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Manufacturer: Westinghouse Electric Corporation (Emerson Ovation product line)
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Product Type: Pulse Accumulator Electronics Module (EMOD)
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Number of Channels: 2 independent pulse input channels
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Input Voltage Ranges: 5VDC, 12VDC, 24VDC, or 48VDC (configuration-dependent via PMOD)
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Speed Classification: Medium speed (distinguished from 1C31147G02 high-speed variant)
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Counter Resolution: 32-bit pulse counter per channel
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Counting Accuracy: ±0.1% of reading
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Signal Types: Single-ended pulse inputs (differential and quadrature supported with appropriate configuration)
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Compatible Personality Modules: 1C31150G01 (Local Power, Common Negative), 1C31150G02 (Local Power, Common Positive), 1C31150G03 (External Field Power)
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Filtering: Software-configurable digital filtering and debounce
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Input Impedance: High-impedance pulse sensing circuit
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Isolation: Standard Ovation channel-to-logic isolation
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Power Consumption: 10W maximum (typical)
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Operating Temperature: -40°C to +70°C (-40°F to +158°F)
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Storage Temperature: -40°C to +85°C (-40°F to +185°F)
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Humidity: 0% to 95% RH (non-condensing)
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Dimensions: Approximately 12.7 cm × 17.8 cm × 2.54 cm (5.0 in × 7.0 in × 1.0 in)
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Weight: 0.2 kg to 0.9 kg (0.5 lbs to 2.0 lbs) depending on configuration
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Mounting: Standard Ovation I/O base or DIN rail mounting
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Required Algorithms: RPACNT (Pulse Count) or RPAWIDTH (Pulse Width) in Ovation Controller
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LED Indicators: Module status and input signal indication
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Non-Volatile Memory: Count retention during power loss (with appropriate configuration)
Part 5: Core Features & Customer Value
Dual-Voltage Range Flexibility: The module’s ability to accept either 5/12V or 24/48V pulse signals (depending on PMOD configuration) accommodates the diverse output levels of industrial pulse devices. For instrumentation engineers, this eliminates the need for external signal conditioning converters when interfacing with low-voltage encoders or high-voltage turbine meters, reducing installation complexity and potential failure points in the measurement chain.
High-Resolution 32-Bit Counting: The 32-bit counter provides a count range exceeding 4 billion pulses, ensuring that flow totalizers and position accumulators never overflow during extended operational periods. In custody transfer applications where missing a single pulse represents lost revenue, this deep count register guarantees continuous accurate accumulation without requiring frequent controller reads to reset counters, reducing communication overhead and improving measurement integrity.
Precision Measurement Accuracy: The ±0.1% accuracy specification supports revenue-grade flow measurement and critical process control applications. For pipeline operators and chemical processors, this precision ensures compliance with American Petroleum Institute (API) and American Gas Association (AGA) measurement standards, eliminating the need for external flow computers in many applications and reducing overall system cost while maintaining custody transfer certification requirements.
Configurable Noise Filtering: Software-configurable digital filtering allows engineers to optimize the trade-off between pulse sensitivity and noise immunity for specific applications. In environments with high electromagnetic interference—such as near variable frequency drives or high-voltage switchgear—appropriate filtering eliminates spurious counts from electrical noise while maintaining responsiveness to genuine flow pulses, ensuring accurate rate calculations and totalization.
Modular Maintenance Architecture: The EMOD/PMOD separation enables rapid field replacement without disturbing field wiring. If the electronics module fails, technicians can replace the 1C31147G01 while leaving the 1C31150 series PMOD and field terminations intact, minimizing exposure of pulse wiring to contamination or disconnection errors. This modularity reduces mean time to repair (MTTR) and eliminates the risk of wiring errors during maintenance on critical flow measurement loops.
WESTINGHOUSE 1C31147G01
Part 6: Typical Applications
Custody Transfer Flow Metering: The 1C31147G01 is extensively deployed in oil and gas pipeline applications to interface with turbine flow meters and positive displacement meters providing pulse outputs proportional to volumetric flow. The 32-bit counter accumulates total flow volumes for billing and inventory management, while the high accuracy ensures compliance with custody transfer standards. When paired with the appropriate PMOD, the module accepts the 24V or 48V pulse outputs common in hazardous area turbine meter installations.
Turbine Speed Monitoring: In power generation and mechanical drive applications, the module monitors magnetic pickup sensors and encoder outputs from steam turbines, gas turbines, and large rotating machinery. The medium-speed counting capability accurately tracks rotational speeds for overspeed protection, load sharing controls, and vibration analysis systems. The galvanic isolation prevents ground loop currents between the turbine bearing housings and the control system electronics.
Process Batch Control: Chemical and pharmaceutical manufacturing facilities utilize the 1C31147G01 to count pulses from positive displacement pumps and metering devices during batch operations. The precise count totalization ensures accurate ingredient addition for batch recipes, while the non-volatile count retention (when configured) prevents batch interruption during power fluctuations, allowing process restart without loss of accumulated volume data.
Water and Wastewater Flow Totalization: In municipal water treatment and industrial wastewater applications, the module interfaces with magnetic flow meters and propeller-type flow sensors providing pulse outputs. The 5/12V input configuration (via appropriate PMOD) accommodates the low-voltage outputs of battery-powered flow meters in remote locations, while the high counter resolution supports daily and monthly flow totalization for regulatory reporting and operational efficiency monitoring.
Conveyor and Position Control: Manufacturing and material handling systems employ the module to count pulses from rotary encoders monitoring conveyor belt position and speed. The pulse accumulation provides precise position feedback for cut-to-length operations, packaging machinery synchronization, and automated storage/retrieval systems, ensuring accurate product placement and reducing waste from positioning errors.
