ABB AI835A

1. Overview

2. Technical Specifications

• Number of Channels: 8 differential input channels, with the 8th channel configurable for cold junction (CJ) temperature measurement
• Signal Range: Linear range of -30 mV to +75 mV; compatible with thermocouple types B, C, E, J, K, N, R, S, T (the AI835A additionally supports D, L, U types)
• Resolution: 15-bit A/D conversion
• Isolation: Mutual isolation between each channel, with a rated isolation voltage of 500 V
• Operating Temperature: -40 °C to +70 °C
• Power Supply: 24 V DC
• Dimensions/Weight: Approximately 90 × 72 × 25 mm, weighing 0.2 kg

3. Product Features

• High-Precision Measurement: Boasts 15-bit resolution, with an error ≤ ±0.1% FS and noise < 0.2% FS, ensuring accurate data collection
• Flexible Configuration: Each channel can be individually set with specific ranges, thermocouple types, or cold junction temperature measurement functions
• Reliability: Industrial-grade design with high temperature resistance and anti-interference capabilities, ideal for severe on-site conditions
• Modular Design: Can be combined with other modules in the S800 I/O system to build a scalable I/O architecture
• Fault Detection: Supports wire break and open-circuit monitoring, enhancing overall system safety

4. Structure and Components

• Front Terminal Blocks: 8 sets of differential input terminals, paired with screw-type wiring for stable connections
• Internal A/D Conversion Unit: 15-bit high-resolution analog-to-digital converter for precise signal transformation
• Isolation Circuitry: Independent isolation for each channel to prevent interference propagation
• Cold Junction Compensation Circuit (Optional): The 8th channel or an external 4-wire Pt100 RTD can be used for thermocouple cold junction compensation
• Enclosure: Metal casing that complies with DIN rail mounting standards for easy installation

5. Typical Application Fields

• Process Control: Continuous measurement of parameters such as temperature, pressure, and flow
• Petrochemical Industry: Acquisition of high-temperature thermocouple signals in refineries and chemical plants
• Paper and Printing: Precision temperature monitoring during production processes
• Power Systems: Temperature detection of transformers and generators to ensure operational safety
• Machine Vision and Robotics: Environmental temperature sensing for optimal equipment performance
• Automated Test Systems: High-precision analog signal input for accurate testing and validation

6. Installation and Maintenance

• Installation Method: DIN rail mounting with secure chassis fixation; wiring is done via screw terminals, with signals connected according to the corresponding channel type
• Wiring Notes: Shielded cables must be used for thermocouples to maintain signal integrity; if the 8th channel is used for cold junction temperature measurement, a 4-wire Pt100 RTD should be connected or the internal fixed temperature can be utilized
• Configuration Steps: In ABB Engineering software (e.g., Control Builder M), set the range, thermocouple type, isolation level, and CJ-channel parameters for each channel
• Maintenance Key Points: Regularly check terminal tightness and cable integrity; use the module’s built-in open/short-circuit detection function for quick fault location; on-site calibration is recommended every 12 months
• Warranty and Support: The manufacturer provides a 12-month warranty, and a global after-sales network offers technical support and spare parts supply