AMM22 | Yokogawa | Multiplexer Module

Description

The Yokogawa AMM22, also cataloged as the AMM22 Multiplexer Module, operates as a dedicated hardware component for process variable scanning within CENTUM CS and CENTUM VP Distributed Control System networks. This high-performance module multiplexes 16 configurable analog input channels, performing 12-bit analog-to-digital conversion on standard current and voltage signals before routing the serialized data to the host DCS controller.

Hardware Specifications

4-20 mA HART Loop Protocol and Channel-to-Channel Isolation

The AMM22 architecture utilizes rigorous channel-to-channel isolation rated at 500 V to suppress ground loops and eliminate common-mode voltage transfer between adjacent instrumentation circuits. Designed to interface with 4-20 mA HART loop protocol field devices, the input circuitry filters electrical noise without dampening high-frequency carrier signals, sustaining a deterministic 100 ms per channel scanning sequence. This isolated analog-to-digital matrix ensures precise signal conversion with an accuracy limit of $\pm0.1\%$ of full scale, preventing localized field-side ground faults from corrupting the internal DCS processor registers.

Frequently Asked Questions

Q: How does a fault on one analog input loop impact the operational continuity of the other 15 channels on the AMM22?

A: Due to the integrated 500 V channel-to-channel isolation, an overvoltage spike, open loop, or short-circuit condition on a single input channel is electrically contained. The remaining 15 analog input loops will continue to scan and convert data normally without scaling errors or measurement drift.

Q: Can the AMM22 accept a mix of different signal types, such as 4-20 mA current and 0-10 V voltage lines simultaneously?

A: Yes. The 16 analog input channels are independently configurable. Field engineers can wire different standard signal formats (4-20 mA, 0-10 V, or 1-5 V) to designated channels, provided the configuration parameter settings in the CENTUM VP / CENTUM CS builder software match the physical wiring layout.

Field Installation Guidelines

• Cabinet Environmental Verification: Mount the module within a clean, non-condensing control enclosure that strictly regulates ambient temperatures between 0 and 55 deg C to prevent thermal component breakdown.
• Shield Grounding Practice: Terminate all instrument cable shields at a single, designated instrument ground bar within the enclosure to minimize electromagnetic interference on the 12-bit conversion matrix.
• Vibration Dampening Controls: Verify that the enclosure installation complies with IEC 60068-2-6 guidelines, maintaining an environment below the 2 G structural vibration threshold at 10-150 Hz.
• Signal Separating Distances: Route low-voltage analog input lines through wiring ducts that are completely isolated from high-voltage AC power distribution circuits to eliminate inductive noise coupling.