Technical Specifications:

• Number of Channels: 4 channels
• Input Signal: 4–20 mA DC (2-wire or 4-wire)
• Input Impedance: 250 Ω (burden resistor, built-in)
• Resolution: 16 bits (65,536 steps)
• Conversion Time: 100 ms per channel (400 ms total for 4 channels)
• Accuracy: ±0.1% of span
• Common Mode Rejection: ≥ 100 dB (50/60 Hz)
• Isolation: 1500 V AC between channels and between channels and backplane (1 minute)
• Power Supply: 5 V DC from backplane bus
• Operating Temperature: 0°C to 55°C
• Dimensions: 25 × 120 × 120 mm (W × H × D) (single-width module)
• Weight: Approximately 0.15 kg
• Certification: CE, UL, CSA

Functional Features:

• Per-channel input range configuration (4–20 mA, 0–20 mA, 0–10 mA via jumper)
• Per-channel linearization (up to 10 points)
• Per-channel alarm setpoints (HH, H, L, LL)
• Per-channel input filter (0.1 to 10 seconds, configurable)
• LED indicators per channel (power, alarm, communication)
• Hot-swappable design

Performance Parameters:

• Linearity: ±0.05% of span
• Temperature Coefficient: ±10 ppm/°C
• Dielectric Withstand Voltage: 1500 V AC, 1 minute
• EMC Compliance: IEC 61000-6-2, IEC 61000-6-4
• MTBF: > 200,000 hours (at 25°C)

Material Composition:

• Module body: FR-4 epoxy glass PCB with conformal coating
• Connector: 40-pin edge connector (gold-plated)
• Terminal block: Phoenix Contact-compatible screw terminals (wire gauge: 22–14 AWG)
• Housing: ABS resin (UL94 V-0)

Structural Features:

• Standard DIN rail module (1/4 width)
• Front-panel terminal block with channel identification labels
• LED status indicators per channel
• DIP switches or software configuration for range and filter settings
• Locking mechanism for secure backplane insertion

Working Principle:
The 4–20 mA input signal flows through the 250 Ω burden resistor, creating a voltage drop of 1–5 V. This voltage is amplified by an instrumentation amplifier and fed to a 16-bit delta-sigma ADC. The ADC converts the analog voltage to a digital value, which is processed by the module’s FPGA. The FPGA applies per-channel linearization, filtering, and scaling. The digital value is transmitted to the DCS controller via the backplane bus. Alarm logic compares the value against user-set limits and triggers a status flag on the backplane.

Advantages & Highlights:

• 16-bit resolution provides high measurement precision
• 1500 V AC isolation ensures noise immunity and safety
• Per-channel configurability eliminates need for external signal conditioners
• Hot-swappable design enables replacement without system shutdown
• Compact 1/4-width module saves rack space

Applicable Industries:

• Oil and gas (refinery, pipeline, offshore)
• Chemical and petrochemical
• Power generation and distribution
• Pulp and paper
• Pharmaceutical
• Water and wastewater

Installation Requirements:

• Insert the module into a CENTUM VP or CENTUM CS I/O carrier
• Ensure the backplane bus voltage is stable at 5 V DC ±5%
• Connect 4–20 mA signals to the terminal block (observe polarity: + to +, – to –)
• Use shielded twisted-pair cables; ground the shield at the DCS end only
• Configure the input range and filter via the DCS engineering station before commissioning

Usage Precautions:

• Do not apply voltage exceeding 30 V DC to the input terminals
• Do not disconnect or connect input signals while the DCS is running (if not hot-swap rated)
• Verify the input signal is within the configured range before enabling the channel
• Replace the module if the accuracy degrades beyond ±0.1% of span
• Keep the module free from conductive dust and excessive humidity

Yokogawa AX01C-C005/CH

Product Name: Yokogawa AX01C-C005/CH Charge Input Module

Model Series: AX01C Series

Product Type: 2-Channel Charge Input Module for Piezoelectric Sensors

Product Overview:
The Yokogawa AX01C-C005/CH is a 2-channel charge input module designed for connection to piezoelectric sensors such as accelerometers and force transducers. The “C005” specifies the charge sensitivity range (5 pC/unit), and “/CH” indicates the China regional variant with Chinese documentation and certification. It is used in CENTUM DCS and FAI systems for vibration, force, and pressure measurement.

Technical Specifications:

• Number of Channels: 2 channels
• Input Signal: Charge (pC) from piezoelectric sensors
• Charge Sensitivity Range: 5 pC/unit (C005), 50 pC/unit (C050), 500 pC/unit (C500) — selectable via jumper
• Input Impedance: > 10¹³ Ω (charge mode)
• Resolution: 20 bits
• Conversion Time: 50 ms per channel (100 ms total)
• Accuracy: ±0.5% of span
• Linearity: ±0.1% of span
• Common Mode Rejection: ≥ 120 dB (50/60 Hz)
• Isolation: 500 V AC between channels, 1500 V AC to backplane (1 minute)
• Low-Pass Filter: 0.5 Hz to 20 kHz (configurable per channel)
• Power Supply: 5 V DC from backplane bus
• Operating Temperature: 0°C to 55°C
• Dimensions: 25 × 120 × 120 mm (W × H × D) (single-width module)
• Weight: Approximately 0.18 kg
• Certification: CE, CCC (China Compulsory Certification)

Functional Features:

• 2 independent charge input channels
• Per-channel charge sensitivity selection (5/50/500 pC)
• Per-channel low-pass filter configuration
• Per-channel alarm setpoints (HH, H, L, LL)
• Per-channel sensor fault detection (open circuit, short circuit)
• LED indicators per channel (power, alarm, sensor fault)
• Hot-swappable design

Performance Parameters:

• Noise Level: < 0.02 pC RMS (at 5 pC range)
• Temperature Coefficient: ±5 ppm/°C
• Dielectric Withstand Voltage: 1500 V AC, 1 minute
• EMC Compliance: IEC 61000-6-2, IEC 61000-6-4
• MTBF: > 200,000 hours (at 25°C)

Material Composition:

• Module body: FR-4 epoxy glass PCB with conformal coating
• Connector: 40-pin edge connector (gold-plated)
• Terminal block: Screw terminals for charge signal input (triaxial connector recommended for low-noise applications)
• Housing: ABS resin (UL94 V-0, China CCC rated)
• Shielding: Metal can around the input amplifier section

Structural Features:

• Standard 1/4-width DIN rail module for CENTUM VP/CS I/O carriers
• Front-panel terminal block with channel labels
• Triaxial BNC connector option for low-noise sensor connection
• DIP switches for range and filter configuration
• LED indicators: Power (green), Alarm (red), Sensor Fault (amber) per channel

Working Principle:
The piezoelectric sensor generates a charge (in picocoulombs) proportional to the measured physical quantity (acceleration, force, or pressure). The charge is transmitted via a low-noise cable to the AX01C input. The module’s ultra-high-impedance charge amplifier (input impedance > 10¹³ Ω) converts the charge to a voltage. A 20-bit delta-sigma ADC digitizes the voltage. The FPGA applies per-channel filtering, linearization, and scaling. The digital value is sent to the DCS controller via the backplane bus. The sensor fault detection circuit monitors the input for open-circuit (infinite impedance) and short-circuit (zero impedance) conditions.

Advantages & Highlights:

• 20-bit resolution provides exceptional measurement precision for low-level charge signals
• Ultra-high input impedance (> 10¹³ Ω) preserves the charge signal without leakage
• Per-channel filter configuration eliminates noise and aliasing
• Sensor fault detection prevents false readings from disconnected or shorted sensors
• Hot-swappable design allows module replacement without system shutdown
• China CCC certification for use in Chinese industrial facilities

Applicable Industries:

• Machinery vibration monitoring (turbines, compressors, motors, pumps)
• Force measurement in manufacturing processes
• Piezoelectric pressure sensing
• Structural health monitoring
• Aerospace and defense (test and measurement)
• Automotive (engine and chassis dynamometer testing)

Installation Requirements:

• Insert the module into a CENTUM VP or CENTUM CS I/O carrier slot
• Connect piezoelectric sensors using low-noise triaxial cables (central conductor: signal, inner shield: driven guard, outer shield: ground)
• Ground the cable shield at the module end only (single-point grounding)
• Configure the charge sensitivity range (5/50/500 pC) to match the sensor output
• Set the low-pass filter cutoff frequency based on the maximum frequency of interest (e.g., 10 kHz for bearing fault detection)

Usage Precautions:

• Do not touch the input terminals with bare hands (body static can damage the high-impedance input)
• Do not exceed the maximum charge input (typically 100,000 pC) — use the C500 range for high-output sensors
• Use triaxial cable with driven guard for sensors located more than 5 meters from the module
• Verify sensor polarity before connecting (reverse polarity inverts the signal)
• Perform a zero-offset check with the sensor unloaded before commissioning
• Replace the module if the noise floor exceeds 0.05 pC RMS