Product Overview

The Yokogawa NFAI135-S51 S2-1 is a precision-engineered Analog Input Module designed for the CENTUM VP and STARDOM control systems. This module functions as a critical interface for current input signals, specifically supporting 4 to 20 mA configurations across 16 isolated channels. It is utilized to convert continuous physical process variables—such as pressure, temperature, and flow—into digital data for processing by the Field Control Station (FCS).

This "S51" variant is characterized by its standard environmental resistance and is optimized for high-density signal integration. The NFAI135-S51 S2-1 ensures high-speed data sampling and superior noise rejection, making it suitable for volatile industrial environments where signal integrity is paramount for process safety and efficiency.

Technical Specifications

• Manufacturer: Yokogawa

• Model Number: NFAI135-S51 S2-1

• Input Channels: 16 channels, isolated

• Input Signal: 4 to 20 mA DC

• Allowable Input Current: 30 mA

• Input Impedance: 250 Ω (during power-on), Min. 500 kΩ (during power-off)

• Accuracy: ±0.1% of full scale

• Data Refresh Cycle: 10 ms

• Withstand Voltage: 1500 V AC between input signals and system

• Power Consumption: Max. 230 mA (5 V DC)

• Weight: 0.24 kg

• Dimensions: 32.8 mm x 106.3 mm x 130 mm

• System Series: CENTUM VP / FIO (Field Network I/O)

Key Technical Characteristics

• High-Resolution Conversion: Employs advanced A/D conversion technology to provide accurate 4-20 mA signal processing with minimal drift.

• Channel Isolation: Features robust galvanic isolation between field circuits and the internal system bus, protecting the controller from field-side electrical surges.

• Hot-Swappable Design: Supports online module replacement, allowing for maintenance and hardware upgrades without interrupting the entire control system's operation.

• Diagnostic Capabilities: Includes internal self-diagnostics to detect and report circuit failures, input over-range conditions, and module hardware errors in real-time.

• Industrial Hardening: Designed to withstand the rigorous demands of petrochemical, power generation, and water treatment facilities, maintaining performance across extended temperature ranges.