Product Core Brief

• Model: NFAI143-H00
• Brand: YOKOGAWA
• Series: FCN-RTU Analog I/O
• Core Function: 16-channel 4-20mA DC analog input module with HART communication support for FCN-RTU systems.
• Product Type: FCN-RTU Analog Input Module
• Key Specs: 16 channels | 4-20mA DC | HART-enabled | Field-to-circuit isolated
• Condition: New Surplus / OEM Original

Key Technical Specifications

• Part Number:
• Product Type: Analog Input Module for FCN-RTU
• Number of Channels: 16
• Input Signal: 4 to 20 mA DC
• HART Communication: Available
• Isolation: Field-to-circuit isolated (point-to-point non-isolated)
• Input Resistance (Power ON): 250Ω
• Input Resistance (Power OFF): 500 kΩ or more
• Allowable Input Current: 24 mA
• Withstanding Voltage: 1500 VAC for 1 minute (input to system)
• Overcurrent Protection: Provided
• Accuracy: ±0.1% of full scale
• Data Refresh Cycle: 10 ms
• Input Step Response Time: 100 ms
• Transmitter Power Supply: 24.0 to 25.5 V (output current limit: 25 mA)
• 2-Wire / 4-Wire Setting: Per channel via setting pin
• Temperature Drift: Max. ±0.01%/°C
• Maximum Current Consumption: 230 mA (5 VDC) / 540 mA (24 VDC)
• External Connection: Pressure clamp terminal or MIL connector cable
• Weight: 0.3 kg

Product Introduction

The NFAI143-H00 is a 16-channel 4-20mA DC analog input module for the YOKOGAWA FCN-RTU controller, with HART communication capability for reading additional device diagnostics from smart transmitters. It is commonly deployed in process plants for temperature, pressure, flow, and level monitoring where field-to-circuit isolation is required but point-to-point isolation is not.

What sets the -H00 variant apart is HART support. That means you can pull device health data, calibration status, and tag information from HART-enabled transmitters without adding separate communication hardware. The 10 ms refresh cycle and ±0.1% accuracy make it suitable for most continuous process control loops.

QA & Testing SOP

• Label and suffix verification: Confirm “NFAI143-H00” marking on the module faceplate. The -H00 suffix specifically denotes HART capability — do not substitute with -SE0, -SE1, or -S50 variants if HART is required.
• Connector and pin inspection: Check the MIL connector or pressure clamp terminals for bent pins, corrosion, or loose contacts. These are common failure points on surplus units.
• Backplane contact check: Inspect the module edge connector for oxidation or physical damage before seating it into an FCN-RTU base.
• Channel signal injection test: Apply a calibrated 4-20mA source to sample channels and verify readings in the FCN-RTU configuration software. Check all 16 channels if time permits.
• HART communication test: Connect a HART-enabled transmitter to at least one channel and confirm that device variables and status can be read through the module.

All units are handled with ESD-safe packaging and labeled with received condition, inspection date, and test status.

Installation Pitfalls & Guide

• ❗ Do not confuse -H00 with -SE0/-SE1. The -SE0 and -SE1 variants are non-HART. If your application requires HART device diagnostics, substituting a non-HART variant will leave you blind to transmitter health data.
• ❗ Verify 2-wire vs. 4-wire jumper settings. Each channel must be configured correctly via the setting pins. A 2-wire transmitter wired as 4-wire will not receive loop power.
• ❗ Check backplane current budget. At 230 mA on the 5 VDC rail and 540 mA on the 24 VDC rail, this module draws significant power. Adding multiple units without verifying the power supply capacity can cause brownouts.
• ❗ Mind the isolation architecture. The module is field-to-circuit isolated but point-to-point non-isolated. A ground fault on one channel can affect others in the same group.

Replacement steps:

1. Log the current FCN-RTU configuration and verify lockout/tagout if performing a cold swap.
2. Disconnect field wiring and remove the failed module from the FCN-RTU base.
3. Seat the NFAI143-H00 firmly and verify the setting pins match the transmitter wiring (2-wire vs. 4-wire).
4. Power up, download configuration if needed, and verify channel readings and HART communication.

Technical FAQ

What is the difference between NFAI143-H00 and NFAI143-SE0? The -H00 supports HART communication; the -SE0 and -SE1 do not. Both are 16-channel 4-20mA input modules with field-to-circuit isolation, but if you need to read smart transmitter diagnostics, you need the -H00 variant.

Can I substitutfor ? Only if HART communication is not required in your application. Electrically, the input specifications are the same, but you will lose the ability to communicate with HART-enabled field devices.

Is this module still in production? The NFAI143 family is listed as discontinued in Yokogawa documentation. Surplus stock is available, but long-term migration planning to a supported platform should be considered.

What transmitter power does it provide? The module supplies 24.0 to 25.5 VDC with a 25 mA current limit per channel, sufficient to power most 2-wire 4-20mA transmitters.

Can I hot-swap this module? The FCN-RTU platform supports hot-swappable I/O in many configurations, but always verify your specific base unit and redundancy setup before removing a live module. Check your system manual first.