PLCs, Power Supplies & Others

Signal Conditioning Overview

The Yokogawa AMM12T operates as a voltage input multiplexer module for the CENTUM CS and VP series distributed control systems. This module accepts multiple analog voltage signals and routes them to a single analog-to-digital converter. It enables high-density input configurations while maintaining measurement accuracy. Process control applications use this module for efficient signal management.

Technical Specifications

The AMM12T measures 128 mm in height and 33 mm in width. Its compact form factor fits standard Yokogawa I/O racks. The module weighs approximately 0.25 kilograms. It draws 450 mA from the +5V DC and 50 mA from the ±15V DC supplies.

Input Architecture and Signal Routing

This module features sixteen single-ended input channels or eight differential pairs. Each channel offers a minimum impedance of 1 MΩ to avoid loading the signal source. The onboard multiplexer ICs sequentially connect each input to the programmable gain amplifier. A precision voltage reference ensures stable conversion results. The multiplexing cycle completes within 100 microseconds per channel. Two multiplexer ICs handle the switching operations efficiently.

Measurement Accuracy and Resolution

The Yokogawa AMM12T achieves 16-bit resolution for precise voltage measurements. The programmable gain amplifier adjusts the input range for optimal signal scaling. A 10 μF tantalum capacitor filters the supply voltage for noise reduction. The module maintains linearity better than 0.01% of full scale. The built-in reference voltage ensures temperature-stable performance.

Connectivity and System Integration

Installing the AMM12T requires one slot in the Yokogawa I/O rack. The module connects to the field wiring through a 50-pin ribbon cable. A green LED confirms normal power and a yellow LED indicates active multiplexing. The module interfaces with the field control unit via the I/O bus. It operates reliably between 0°C and 50°C ambient temperatures. Proper shielding of the input cables reduces measurement errors.

Reliability and Maintenance

The Yokogawa AMM12T delivers consistent performance in continuous process environments. Its solid-state multiplexing design eliminates mechanical relay wear. The module undergoes factory calibration for guaranteed accuracy. Regular verification against a known voltage source ensures measurement integrity. The module’s compact design allows dense installation in large systems.

Details