Yokogawa AMM25T Analog Input Multiplexer Module

Configured for multi-channel signal consolidation in CENTUM VP and CENTUM CS automation architectures, the Yokogawa AMM25T (AMM25T Analog Input Multiplexer Module) provides direct physical/electrical execution of high-precision measurement for industrial instrumentation.

Hardware Specifications

Process Control and DCS Instrumentation Characteristics

• 4-20 mA HART loop protocol: The module architecture manages standard process current loops, facilitating the reliable acquisition of sensor data while maintaining compatibility with legacy analog instrumentation.
• FOUNDATION Fieldbus / Profibus PA connectivity: The multiplexer integrates into the Yokogawa control fabric, ensuring that consolidated field signals are correctly formatted for high-speed transmission across the DCS network.
• Channel-to-channel isolation: Each input channel is protected by channel-to-bus galvanic isolation barriers, preventing ground loop interference and protecting the backplane from common-mode electrical noise.
• Cold junction compensation (CJC): Internal thermal management circuitry ensures measurement stability and precision when interfacing with low-level millivolt signals typical of temperature transmitters and thermocouple loops.

Frequently Asked Questions

Q: Does the AMM25T support hot-swapping?

A: Yes. The module is designed for hot-swapping on standard Yokogawa I/O baseplates. Ensure the DCS application is configured to force the input channels to a fail-safe state prior to module removal to prevent downstream control disturbances.

Q: Can the module handle both current and voltage inputs simultaneously?

A: Yes. The module is engineered to accept both 4-20 mA and millivolt input types; refer to the DCS engineering station software to verify channel-level configuration and scaling parameters.

Field Installation Guidelines

• Mounting: Seat the AMM25T firmly into the designated I/O baseplate slot. Ensure the module locking mechanism is engaged to maintain constant electrical contact with the backplane communication and power rails.
• Grounding: Connect the I/O baseplate chassis to the cabinet’s instrument earth bus. A low-impedance ground connection is mandatory to ensure the efficacy of the channel-to-bus isolation and to protect the internal circuitry from electrostatic discharge.
• Wiring: Terminate field wiring for transmitters at the baseplate terminal blocks. Maintain at least 150 mm of separation between analog input loops and high-power AC cabling to mitigate inductive interference and maintain measurement accuracy within the ±0.1 % FS rating.