Description

Yokogawa AMM21T Thermocouple Input Multiplexer Module

The Yokogawa AMM21T, also cataloged as the AMM21T Thermocouple Input Multiplexer Module, operates as a dedicated hardware component for consolidating multiple thermocouple signals within CENTUM VP and CENTUM CS distributed control systems.

HardwareSpecifications

Parameter	Specification
ModelBrand	Yokogawa AMM21T
Origin	Japan
Weight	Approximately 200 g
Dimensions	95 mm x 115 mm x 40 mm
OperatingTemp	-10 degC to 55 degC
StorageTemp	-20 degC to 70 degC
Humidity	10% to 90% RH non-condensing
PowerConsumption	5 W maximum per module
InputChannels	4 channels analog input
Resolution	16-bit
SamplingRate	10 MS/s per channel
Bandwidth	3 MHz maximum frequency response
InputVoltageRange	60 VDC + AC peak maximum
IsolationVoltage	200 V channel-to-channel
Accuracy	±0.1% of reading typical
NoiseLevel	±4 μV typical
Communication	SMARTDAC+ proprietary bus interface
Mounting	DIN rail or wall mount compatible
Protection	IP20 front panel

Process Control Specifics

• Supports cold junction compensation (CJC) for all connected thermocouples to ensure linearized temperature readings.
• Channel-to-channel isolation prevents cross-interference between adjacent measurement circuits.
• Integrated signal conditioning for low-noise operation at ±4 μV typical.
• Compatible with 4-20 mA or system-level digital output conversion.

Frequently Asked Questions

Q: Can the AMM21T support hot-swapping in the I/O nest?
A: The module is not designed for hot-swapping; power must be removed before insertion or removal to prevent damage to the backplane or module circuitry.

Q: What is the maximum sampling rate per channel?
A: Each analog input channel can sample up to 10 MS/s; simultaneous multi-channel sampling may be limited by the backplane bus bandwidth.

Q: Does the module include built-in thermocouple fault detection?
A: Yes, sensor burnout and disconnection are detected, and the affected channel is isolated to prevent propagation to other channels.

Field Installation Guidelines

• Install on a DIN rail or secure wall mount; ensure module orientation allows proper airflow.
• Maintain shielded cabling grounded at a single point to minimize noise pickup.
• Route analog thermocouple signals separately from power or switching circuits to reduce EMI.
• Verify backplane connection integrity before system power-up to ensure proper channel addressing.
• Avoid mechanical stress on terminal connectors; torque screws to manufacturer-specified limits.

Specifications

• Brand: Yokogawa

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems