The YOKOGAWA NFAI841-S00 analog input module is an industrial grade signal acquisition component launched by Yokogawa Electric in Japan. It belongs to the NFA series analog I/O module camp and is core compatible with Yokogawa CENTUM CS 3000 distributed control system (DCS) and FCN autonomous controller. It is a key signal bridge between industrial sites and control systems. Its core function is to accurately convert the analog signals (such as current and voltage signals) output by on-site sensors and transmitters into digital signals, transmit them to the upper control system for processing and analysis, and achieve real-time monitoring of core process parameters such as temperature, pressure, flow rate, and liquid level. This module adopts an 8-channel design, supports multiple standard analog signal inputs, has high-precision acquisition and stable operation characteristics, and integrates isolation design and flexible configuration functions to meet the application requirements of complex industrial environments. The modular structure design makes it easy to install and maintain, and meets the dense layout requirements of industrial automation systems. It is widely used in industries such as petrochemicals, power, and manufacturing that require extremely high reliability in signal acquisition.
Product Overview
The YOKOGAWA NFAI841-S00 analog input module is an industrial grade signal acquisition component launched by Yokogawa Electric in Japan. It belongs to the NFA series analog I/O module camp and is core compatible with Yokogawa CENTUM CS 3000 distributed control system (DCS) and FCN autonomous controller. It is a key signal bridge between industrial sites and control systems. Its core function is to accurately convert the analog signals (such as current and voltage signals) output by on-site sensors and transmitters into digital signals, transmit them to the upper control system for processing and analysis, and achieve real-time monitoring of core process parameters such as temperature, pressure, flow rate, and liquid level. This module adopts an 8-channel design, supports multiple standard analog signal inputs, has high-precision acquisition and stable operation characteristics, and integrates isolation design and flexible configuration functions to meet the application requirements of complex industrial environments. The modular structure design makes it easy to install and maintain, and meets the dense layout requirements of industrial automation systems. It is widely used in industries such as petrochemicals, power, and manufacturing that require extremely high reliability in signal acquisition.
Specification parameters
The YOKOGAWA NFAI841-S00 analog input module ensures the reliability and accuracy of signal acquisition with precise technical parameters. The core specification parameters have been verified at the industrial level, and the specific details are as follows:
-Basic information: Model number NFAI841-S00, manufacturer YOKOGAWA (Yokogawa Electric), product type is analog input module, country of origin is Japan; The core adaptation system consists of Yokogawa CENTUM CS 3000 DCS and FCN autonomous controllers;
-Channel and signal specifications: Equipped with 8 analog input channels, supporting ± 20mA current signal and ± 10V voltage signal input, compatible with 2-wire/4-wire transmitter connections; The input impedance is 10M Ω to ensure that the signal acquisition process does not interfere with the operation of the source device;
-Acquisition accuracy and response performance: Using a 16 bit A/D conversion chip, the sampling rate reaches 50Hz, ensuring high resolution and timeliness of the collected data; Excellent input accuracy, with temperature drift controlled within ± 0.1%/10 ℃, effectively resisting the impact of environmental temperature changes on acquisition accuracy;
-Power parameters: Adopting a dual power supply design, the typical power supply voltage is 5V DC and 24V DC, with a maximum power consumption of 2.5W. It has a power reverse protection function to prevent module damage caused by reverse polarity of the power supply;
-Environmental adaptability parameters: working temperature range is -20 ℃~60 ℃, storage temperature range is -40 ℃~80 ℃; The relative humidity adaptation range is 10%~90% RH (without condensation); The protection level reaches IP20, which can adapt to industrial site environments with high dust and humidity fluctuations;
-Physical and installation parameters: Adopting a compact design, the external dimensions (length x width x height) are approximately 110mm x 35mm x 100mm (slightly different channel markings, with additional specifications of 76mm x 116mm x 26mm recorded), weighing approximately 300g; the installation method is 35mm industrial standard DIN rail installation, suitable for dense layout requirements inside the control cabinet;
-Special functional parameters: Supports HART communication function (please refer to the dedicated document GS 34P02Q53-01E); Equipped with isolated simulated pressure clamping terminals (NFTI3S-00) for quick wiring of on-site equipment; Equipped with circuit open circuit detection function, with an open circuit detection resistance of ≥ 340k Ω.
Performance characteristics
The YOKOGAWA NFAI841-S00 analog input module integrates Yokogawa Electric's core technology in the field of industrial signal acquisition, and has multiple performance advantages that are suitable for industrial scenarios, comprehensively ensuring the accuracy and reliability of signal acquisition:
-Multi signal compatibility and flexible adaptation: supports multiple standard analog signal inputs such as ± 20mA current and ± 10V voltage, compatible with 2-wire/4-wire transmitters, and can flexibly configure channel parameters according to the type of sensor on site, without the need for additional signal conversion equipment, with strong versatility;
-High precision acquisition and stable operation: using 16 bit high-precision A/D conversion technology and optimized signal processing algorithms, combined with low temperature drift design, to ensure excellent acquisition accuracy can still be maintained in a wide temperature environment; The 50Hz sampling rate can quickly capture changes in process parameters, providing real-time and accurate data support for the control system;
-Isolation design and anti-interference capability: Isolation design is adopted between input and output, which can effectively block ground loop interference and electromagnetic interference in industrial sites; It is also recommended to use shielded wiring to further enhance anti-interference performance and ensure stable signal acquisition in strong interference environments such as frequency converters and high-power motors;
-Convenient installation and maintenance: adopting modular structure and standard DIN rail installation design, it can be quickly integrated into the control unit of Yokogawa DCS system; Equipped with dedicated pressure clamping terminals, the wiring operation is convenient and easy to maintain in the later stage; The module status can be monitored in real-time by the upper system, making fault location efficient;
-Rich feature expansion: Supports HART communication function, can achieve bidirectional communication with smart transmitters with HART protocol, not only can collect process parameters, but also can obtain the working status of the transmitter and perform remote parameter configuration; Equipped with circuit open circuit detection function, it can promptly detect sensor wiring faults and ensure the integrity of the acquisition link;
-Industrial grade environmental adaptability: Using industrial grade electronic components and rigorous production processes, it has a wide temperature working range and IP20 protection level. It can operate continuously and stably in harsh industrial environments with high dust and humidity fluctuations, and has excellent mean time between failures (MTBF) performance.
Precautions
To ensure the stable operation of the YOKOGAWA NFAI841-S00 analog input module, extend the service life of the equipment, and ensure the accuracy of data collection and production process safety, the following precautions must be strictly followed during installation, wiring, operation, and maintenance:
-Preparation and inspection before installation: Before installation, it is necessary to carefully read the product user manual and related documents (such as HART communication instructions, on-site connection specifications), familiarize oneself with the installation requirements, electrical parameters, and configuration rules of the module; After opening the box, it is necessary to check whether the appearance of the module is intact, and whether the terminals, buckles, and other components are intact. If there is any damage or abnormality, the use should be stopped immediately and authorized service providers of Yokogawa Electric should be contacted;
-Installation environment and layout requirements: Avoid installing modules directly above the heating unit to prevent radiation heat from affecting them; Not directly exposed to airflow, and not adjacent to CPU modules (NFCP501/NFCP502) and power modules (NFPW44x); It can only be installed adjacent to designated modules such as NFAT141 and NFAR181. Other modules require reserved slots to ensure heat dissipation and anti-interference performance;
-Electrical wiring specifications: All relevant power sources must be disconnected before wiring, and live wiring is strictly prohibited; The analog signal line, switch signal line, and power line need to be wired separately. It is recommended to use shielded twisted pair cables for analog signals, and the shielding layer should be reliably grounded at one end to reduce electromagnetic interference; When wiring, it is necessary to strictly distinguish between signal types and terminal definitions to ensure the correct wiring of 2-wire/4-wire transmitters and avoid module or sensor damage caused by misconnection;
-Power and load matching: Confirm that the power consumption of the module does not exceed the rated output of the supporting power module (5V DC, 24V DC), to avoid power overload and abnormal module operation; Strictly distinguish the positive and negative poles of the power supply during wiring to prevent reverse connection and damage to the internal circuit of the module;
-Explosion proof and intrinsic safety requirements: If applied to explosion-proof scenarios, reference should be made to the STARDOM FCN/FCJ Installation Guide for selection and installation; Inherent safety applications require the use of isolation barriers, and it is strictly prohibited to connect Zener barriers to avoid causing safety accidents;
-Running process monitoring: During the running process, the working status and data collection of the module need to be monitored in real time through the upper system. If abnormal fluctuations or fault alarms are found in the data, the power supply, wiring, sensors, and the module itself should be checked in a timely manner; Regularly calibrate the accuracy of the module with a standard signal source to ensure compliance with process requirements;
-Fault handling and maintenance: When a module malfunctions, it is necessary to disconnect the power supply before troubleshooting. It is strictly prohibited to disassemble the module or check the internal circuit while it is live; Troubleshooting should follow the principle of "external first, internal second", with priority given to checking the wiring, sensors, and power supply. If there are no external issues, repairs must be carried out by authorized professionals from Yokogawa. Non professionals are strictly prohibited from disassembling the module casing; During daily maintenance, a dry cloth can be used to clean the dust on the surface of the module, check whether the terminals are loose or oxidized, and promptly deal with any problems found;
-Configuration operation specifications: Module parameter configuration needs to be completed through the upper system or specialized tools. Before configuration, the original parameters need to be backed up, and the channel signal type, range, and other parameters should be accurately set according to the type of sensor on site; After the configuration is completed, testing and verification are required to ensure accurate data collection and avoid monitoring failures caused by configuration errors.





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