Yokogawa NFAI141-S00 S2 Analog Input Module

Technical Dossier

Product Details And Specifications

Yokogawa NFAI141 Series: Comprehensive Module Range and Technical Overview

The Yokogawa NFAI141 series is a family of analog input modules deployed within the Yokogawa CENTUM VP and CENTUM CS 3000 Distributed Control Systems (DCS). These modules occupy a critical position in global heavy industry installations, including petrochemical complexes, nuclear power facilities, crude oil refineries, LNG terminals, and continuous process manufacturing plants. The NFAI141 series handles 4–20 mA and voltage-based field signal acquisition, converting analog process variables into digital values for the CENTUM VP field control station (FCS). Installed base spans facilities across Asia-Pacific, the Middle East, and Europe, where CENTUM VP remains the dominant DCS platform for large-scale continuous process control.

The Evolution of NFAI141 Architecture

The NFAI141 module traces its lineage to the Yokogawa CENTUM CS 3000 platform introduced in the late 1990s, which standardized the node-based I/O architecture using the Vnet/IP control network. Early NFAI141 revisions (suffix -S00) established the baseline 16-channel analog input specification with HART pass-through capability. Subsequent suffix variants introduced incremental improvements in channel isolation, EMC compliance ratings, and firmware compatibility with CENTUM VP R4.x and R6.x releases.

The transition from CS 3000 to CENTUM VP (circa 2008–2012) maintained backward hardware compatibility for NFAI141 modules, allowing existing field wiring and marshalling cabinets to remain in service. However, firmware suffix levels (S1, S2, S3) introduced dependency on specific FCS software revisions. The S2 suffix, as in the NFAI141-S00 S2, denotes a specific hardware revision level that is compatible with CENTUM VP R5.03 and later. As CENTUM VP itself transitions toward the CENTUM VP R6 and the newer Yokogawa OpreX platform, NFAI141 modules have entered the mature/end-of-active-production phase. Yokogawa continues to provide long-term maintenance support (LTMS) for installed base, but new procurement relies on authorized distributors and certified secondary-market suppliers.

NFAI141 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified NFAI141 series and closely related CENTUM VP analog I/O modules. Each entry reflects a distinct hardware revision, channel configuration, or functional variant within the Yokogawa field I/O module ecosystem.

Analog Input Modules (AI)

• NFAI141-S00 S2: 16-ch analog input, 4–20 mA/voltage, HART, CENTUM VP FCS compatible, HW rev S2
• NFAI141-S00 S1: 16-ch analog input, 4–20 mA/voltage, HART, HW rev S1, CS 3000 / VP R4.x
• NFAI141-S00 S3: 16-ch analog input, 4–20 mA/voltage, HART, HW rev S3, VP R6.x firmware
• NFAI141-S10: 16-ch analog input with enhanced channel isolation, intrinsically safe variant
• NFAI141-S20: 16-ch analog input, extended temperature range, offshore/hazardous area rated
• NFAI841-S00: 8-ch high-density analog input, 4–20 mA, HART multiplexed, CENTUM VP FCS
• NFAI841-S10: 8-ch analog input, IS barrier integrated, Zone 1 hazardous area deployment

Analog Output Modules (AO)

• NFAO141-S00: 16-ch analog output, 4–20 mA, HART, CENTUM VP FCS, standard revision
• NFAO141-S00 S2: 16-ch analog output, 4–20 mA, HART, HW rev S2, VP R5.03+
• NFAO841-S00: 8-ch analog output, 4–20 mA, HART, high-density FCS node

Digital Input / Digital Output Modules (DI/DO)

• NFDI141-S00: 32-ch digital input, 24 VDC, dry contact / wet contact selectable, CENTUM VP
• NFDI141-S10: 32-ch digital input, IS-rated, Zener barrier compatible, Zone 1
• NFDO141-S00: 32-ch digital output, 24 VDC transistor, CENTUM VP FCS node
• NFDO141-S10: 32-ch digital output, relay output variant, 250 VAC/30 VDC contact rating

Communication & Power Modules

• NFCP701-S00: Field control station (FCS) CPU module, CENTUM VP, Vnet/IP dual-redundant
• NFPS701-S00: FCS power supply module, 24 VDC output, redundant pair configuration
• NFBU711-S00: Node unit base module, 16-slot I/O bus backplane, CENTUM VP FCS

Sourcing Hard-to-Find & Obsolete NFAI141 Parts

The NFAI141 series has entered the mature phase of its product lifecycle. Yokogawa's official end-of-active-production designation means that new module procurement through standard distribution channels is increasingly constrained. Lead times from authorized sources can extend to 26–52 weeks for specific suffix revisions.

DriveKNMS maintains a dedicated inventory of NFAI141 modules — including the NFAI141-S00 S2 and adjacent suffix variants — sourced from decommissioned plant assets, authorized surplus channels, and factory-refurbished stock. All units are catalogued by hardware revision suffix to ensure firmware compatibility with the target CENTUM VP FCS software version. DriveKNMS provides lifecycle extension support for facilities operating CENTUM CS 3000 and CENTUM VP systems beyond Yokogawa's standard support window, covering module-level replacement, cross-reference to compatible successor modules, and technical documentation for integration into existing I/O node configurations.

Quality Control for the NFAI141 Range

NFAI141 modules incorporate a multi-layer backplane bus architecture connecting the analog front-end (AFE) signal conditioning circuitry to the FCS node communication interface. DriveKNMS applies a structured test protocol specific to this module family:

• Channel-level signal injection: Each of the 16 analog input channels is stimulated with calibrated 4 mA, 12 mA, and 20 mA reference signals. Output digital values are verified against the module's published accuracy specification (±0.1% of span).
• HART communication verification: HART pass-through functionality is tested on a minimum of four channels per module using a HART communicator to confirm secondary variable transmission integrity.
• Backplane bus continuity: The node bus connector (96-pin DIN) is inspected for pin deformation and contact oxidation. Bus communication is verified under simulated FCS node load conditions.
• Firmware revision identification: Hardware suffix (S1/S2/S3) is confirmed via module label and internal firmware register read-back to prevent suffix mismatch in target FCS configurations.
• Burn-in cycle: Modules are subjected to a 48-hour powered burn-in at 40°C ambient to screen for early-life component failures prior to dispatch.