Yokogawa AAT141-S50 S2 TC/mV Input Module 16-Channel

Product Overview

The AAT141-S50 S2 (AAT141) is a high-density, 16-channel isolated input module specifically engineered for the Yokogawa CENTUM VP distributed control system (DCS). This module specializes in the precise acquisition of low-level signals from thermocouples (TC) and millivolt (mV) sources, covering a wide range of industrial sensors including Types R, J, K, E, T, B, S, and N. Designed for mission-critical thermal monitoring in industries such as steel manufacturing, glass production, and power generation, the AAT141 provides exceptional signal integrity with a 1500 V AC withstanding voltage. Its isolated architecture eliminates multi-point ground errors, which is vital for preventing temperature measurement drifts. By supporting dual-redundant configurations and offering a 1-second data refresh cycle, this module ensures continuous process visibility and minimizes the risk of costly downtime due to sensor signal interference or hardware failure.

Suffix Breakdown

The AAT141-S50 model name identifies the hardware standards and safety certifications of the unit:

• -S: Designates the Standard type hardware, optimized for high-reliability data acquisition within the CENTUM VP FIO subsystem.

• 5: Indicates the module is manufactured with no explosion protection, intended for use in safe areas or within properly purged and pressurized control cabinets.

• 0: Specifies the Basic type configuration, providing standard 16-channel thermocouple and millivolt processing capabilities without additional specialized modifiers.

• S2: Represents the hardware style/revision code, ensuring compatibility with the latest STARDOM and CENTUM node units.

Technical Specifications

Technical FAQs

Does the AAT141 support grounded or non-grounded thermocouples?

It is highly recommended to use non-ground type thermocouples. Because the AAT141 is an isolated module, using ground type thermocouples can result in multi-point grounding across different channels, which often leads to significant temperature measurement errors.

How does ambient temperature affect the Reference Junction Compensation (RJC)?

The RJC accuracy is optimized for stable environments. In a standard node, accuracy is plus/minus 1 deg C between 15 and 45 deg C. If the environment fluctuates or is at extremes (-20 to 15 deg C or 45 to 70 deg C), the RJC error margin increases to plus/minus 2 deg C.

Can I mix thermocouple types and millivolt inputs on a single module?

Yes. Each of the 16 channels can be individually configured for either TC or mV input, providing maximum flexibility for diverse sensor arrays within a single I/O slot.

Engineering & Installation Guide

• Thermal Isolation: The AAT141 is highly sensitive to radiated heat. Do not install heat-radiating units (such as power supplies or CPU modules like CP461/CP451) directly beneath or adjacent to this module. If a non-compatible I/O module must be placed nearby, leave at least one empty slot on each side to act as a thermal buffer.

• Airflow Management: Avoid installing the module in areas where direct, high-velocity airflow (such as cabinet fans) hits the pressure clamp terminals. If a fan is located in the upper cabinet space, mount the module at least 133 mm (3 units) below the fan to prevent RJC instability.

• Wiring Consistency: When using millivolt inputs, the wiring resistance for signal cables must be identical to maintain accuracy. Use a nominal conductor cross-sectional area of 1.25 mm2 or less and ensure all terminal connections are torqued correctly to prevent contact resistance drift.

• RJC Stability: Accuracy specifications are based on stable thermal conditions. If the cabinet door is opened or if a sudden temperature change occurs, allow sufficient time for the pressure clamp terminal temperature to stabilize before trusting high-precision measurements.