PLCs, Power Supplies & Others

Product Overview

The Yokogawa AST143 measures temperature and low-level voltage signals from thermocouples and millivolt sources. This module provides 8 isolated input channels for precise thermoelectric and DC voltage measurements. It converts these analog signals into digital values for the control system. The unit integrates seamlessly into Yokogawa CENTUM and ProSafe-RS platforms.

Technical Specifications

Physical Dimensions and Mounting

This module measures 130 mm in height, 30 mm in width, and 100 mm in depth. The unit weighs approximately 0.30 kg. It mounts directly onto a DIN rail within the system cabinet. The front panel includes 8 LED indicators for channel monitoring. These LEDs show input status and fault conditions clearly.

Electrical Interface and Sensor Wiring

A 37-pin D-sub connector provides the primary interface for all thermocouple and mV wiring. The module supports 8 different thermocouple types with built-in linearization. Each channel includes a precision cold junction compensation sensor. The high input impedance of 10 MΩ minimizes loading errors on millivolt signals. Thermocouple sensors like K, T, and J types connect directly to these terminals. Millivolt sources like DC shunts and load cells also connect without additional conditioning.

Performance and Signal Processing

The AST143 delivers 16-bit resolution for accurate temperature and voltage measurement. It samples each channel at 10 times per second for responsive monitoring. The module filters input signals to reject 50 Hz and 60 Hz noise effectively. The built-in CJC sensor automatically compensates for terminal block temperature variations. Furthermore, the module performs continuous diagnostics for open-circuit detection. It reports sensor break conditions to the main controller immediately.

Installation and System Integration

You can install this module in any available slot within the Yokogawa CENTUM chassis. The backplane automatically handles address assignment and power distribution. Always configure the thermocouple type using the system engineering software. For critical temperature measurements, implement redundant modules for failover protection. Use the correct thermocouple extension wire type for accurate readings.

Environmental Compliance and Certification

This module carries CE marking and UL recognition for industrial applications. It also complies with RoHS and WEEE environmental directives. The conformal coating protects the PCB against moisture and dust ingress. This coating ensures long-term reliability in demanding plant environments.

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