Yokogawa NFAR181-S00 S2 Analog Input Module

Technical Dossier

Product Details And Specifications

Yokogawa NFAR Series: Comprehensive Module Range and Technical Overview

The Yokogawa NFAR series of analog input modules occupies a critical position in global heavy-industry distributed control systems (DCS). Deployed across petrochemical complexes, nuclear power facilities, LNG terminals, and crude oil refineries, NFAR modules serve as the primary field-signal acquisition layer within Yokogawa's CENTUM CS 3000 and CENTUM VP platforms. Their 4–20 mA and thermocouple/RTD input capabilities, combined with HART pass-through support on select variants, make them the standard reference for process variable acquisition in safety-instrumented and continuous-process environments. Installed base counts in the tens of thousands of nodes across Asia-Pacific, the Middle East, and Europe confirm their role as a backbone I/O component in long-lifecycle plant automation architectures.

The Evolution of NFAR Architecture

The NFAR module lineage traces to Yokogawa's CENTUM CS platform introduced in the mid-1990s, where analog input acquisition was handled by discrete, slot-addressable I/O cards communicating over the V-net/IP fieldbus backbone. Early NFAR variants operated with fixed 16-channel configurations and required external signal conditioners for thermocouple linearization. With the transition to CENTUM CS 3000 (circa 2000–2005), Yokogawa standardized the NFAR form factor to a 19-inch rack-mount card with integrated cold-junction compensation and on-board A/D conversion at 16-bit resolution. The CENTUM VP generation (2008–present) introduced firmware-level HART multiplexing on NFAR-H suffix variants, enabling asset management integration without additional hardware. The S2 suffix on the NFAR181-S00 S2 denotes a second-generation hardware revision with improved EMC shielding and extended operating temperature tolerance (−20°C to +70°C). Compatibility between S1 and S2 hardware revisions is maintained at the firmware and backplane connector level, allowing field substitution without controller reconfiguration. As CENTUM CS 3000 has entered end-of-active-support status, NFAR modules for that platform are now sourced exclusively through authorized spare-parts channels.

NFAR Series Full Catalog & Functionalities (SKU List)

The following catalog covers verified NFAR series SKUs across analog input sub-types, hardware revisions, and channel configurations. All models are compatible with CENTUM CS 3000 and/or CENTUM VP unless otherwise noted.

NFAR181-S00 S2: 16-ch analog input module, 4–20 mA, 16-bit ADC, S2 revision, CENTUM VP.
NFAR181-S00 S1: 16-ch analog input module, 4–20 mA, 16-bit ADC, S1 revision, CS 3000/VP.
NFAR181-H00 S2: 16-ch analog input with HART pass-through, S2 revision, CENTUM VP.
NFAR181-H00 S1: 16-ch analog input with HART pass-through, S1 revision, CS 3000/VP.
NFAR131-S00 S2: 8-ch analog input module, 4–20 mA, compact slot format, CENTUM VP.
NFAR131-S00 S1: 8-ch analog input module, 4–20 mA, CS 3000/VP compatible.
NFAR131-H00 S2: 8-ch analog input with HART multiplexing, CENTUM VP.
NFAR141-S00 S2: 16-ch thermocouple/mV input module, integrated CJC, CENTUM VP.
NFAR141-S00 S1: 16-ch thermocouple/mV input, S1 revision, CS 3000/VP.
NFAR151-S00 S2: 16-ch RTD/resistance input module, 3-wire PT100, CENTUM VP.
NFAR151-S00 S1: 16-ch RTD/resistance input, S1 revision, CS 3000/VP.
NFAR161-S00 S2: 16-ch high-speed analog input, 50 ms scan, CENTUM VP.
NFAR161-H00 S2: 16-ch high-speed analog input with HART, CENTUM VP.
NFAR191-S00 S2: 32-ch multiplexed analog input, high-density rack, CENTUM VP.
NFAR191-H00 S2: 32-ch multiplexed analog input with HART, high-density, CENTUM VP.
NFAR111-S00 S2: 4-ch isolated analog input, galvanic isolation per channel, CENTUM VP.
NFAR121-S00 S2: 8-ch isolated analog input, galvanic isolation per channel, CENTUM VP.

Sourcing Hard-to-Find & Obsolete NFAR Series Parts

Quality Control for the NFAR Range

NFAR modules present specific test challenges due to their multi-channel analog front-end architecture and backplane bus communication protocol. DriveKNMS applies a structured validation procedure to every NFAR unit processed: (1) Visual inspection of the A/D converter IC, signal conditioning op-amp array, and backplane edge connector for corrosion, cold solder joints, or mechanical damage. (2) Powered functional test using a calibrated current source (4 mA, 12 mA, 20 mA) applied to each channel independently, with output values verified against a reference CENTUM VP controller node. (3) HART communication verification on H-suffix variants using a HART modem and field device simulator to confirm pass-through integrity at 1200 baud. (4) Cold-junction compensation accuracy check on thermocouple-input variants (NFAR141) across the full −20°C to +70°C operating range. (5) Backplane bus load test confirming correct V-net/IP token-passing behavior under simulated multi-node traffic. Units failing any stage are quarantined and documented; no failed unit is relabeled or re-offered as functional stock.