Alstom AL81G

Core Technical Specifications

1. Analog Input Channels: 16 single-ended channels, configurable as 8 differential isolated channels
2. ADC Resolution: 24-bit high-resolution analog-to-digital converter
3. Full-Scale Accuracy: ±0.05% FS at 25°C ambient temperature
4. Supported Input Signal Types: 4–20 mA DC current loop, ±10 V DC voltage signal
5. Input Impedance: >1 MΩ (voltage mode), 250 Ω fixed shunt (current mode)
6. Channel Isolation Rating: 1500 Vrms channel-to-system ground galvanic isolation
7. Max Sampling Rate: 1000 samples per second global synchronous sampling
8. On-Board Buffer Memory: 64 MSample local data storage buffer
9. Power Supply Requirement: 24 V DC ±10%, maximum power consumption 28 W
10. Communication Interfaces: Proprietary Alstom Turbine Guard backplane bus, RS-485 Modbus RTU
11. Operating Temperature Range: -20 °C to +70 °C
12. Storage Temperature Range: -40 °C to +85 °C
13. Physical Dimensions: 200 mm (L) × 150 mm (W) × 50 mm (D)
14. Net Weight: 1.2 kg
15. Ingress Protection Class: IP65 (sealed board assembly; IP20 when installed inside control cabinet)

Functional Features

1. Hardware synchronous multi-channel sampling with software trigger, hardware threshold trigger, and continuous streaming trigger modes
2. Built-in multi-stage low-pass anti-aliasing filter configurable via firmware
3. Automatic cold-junction temperature compensation for thermal drift elimination
4. Overvoltage, overcurrent, and reverse-polarity input protection on every analog channel
5. Real-time channel fault self-diagnosis with front-panel LED status indicators
6. Lossless data caching to avoid signal dropout during bus communication interruptions
7. Firmware upgradable via backplane bus without physical disassembly

Working Principle

Material & Structural Characteristics

• Main PCB substrate: FR-4 high-temperature flame-retardant circuit board
• Signal isolation components: Ceramic capacitive isolation transformers
• Housing material: Cold-rolled steel with electrostatic anti-corrosion black coating
• Connector type: Gold-plated terminal block for field wiring; gold-plated edge connector for rack backplane insertion
• Mechanical structure: Standard 3U rack card form factor with anti-vibration mounting clips

Core Advantages & Highlights

1. Industry-leading 24-bit resolution with ultra-low temperature drift for long-term stable measurement
2. Full channel-to-ground isolation eliminates ground loop interference in multi-sensor distributed systems
3. Large on-board sample buffer supports uninterrupted recording during temporary communication loss
4. Direct plug-and-play compatibility with all Alstom Turbine Guard power monitoring platforms
5. Wide operating temperature range adapts to unconditioned factory and power station cabinet environments

Applicable Industries

Installation Mandatory Requirements

1. Install only inside standard 19-inch industrial control rack with horizontal ventilation clearance ≥20 mm above and below the module
2. Mount rack vibration dampers if equipment base vibration exceeds 0.5 g continuous acceleration
3. Separate analog signal wiring from high-voltage power cables by minimum 15 cm distance
4. Power input must connect to isolated 24 V DC power supply with surge protection module
5. Complete full system calibration after physical installation before operational commissioning

Operation & Maintenance Precautions

1. No hot-plugging during live power operation; cut auxiliary power before inserting/removing the module
2. Avoid direct exposure to water vapor, oil mist, and conductive dust; maintain cabinet internal humidity ≤85% non-condensing
3. Execute full channel calibration every 12 months to retain factory-specified measurement accuracy
4. Do not modify on-board jumper or filter configuration without official Alstom service documentation
5. Store spare modules in temperature-controlled dry cabinet with anti-static packaging