{"product_id":"yokogawa-nfai135-s50-8-channel-isolated-analog-input-module","title":"Yokogawa NFAI135-S50 8-Channel Isolated Analog Input Module","description":"\u003cp\u003eThe Yokogawa NFAI135-S50 is an 8-channel isolated analog input module for receiving 4 to 20 mA signals from field transmitters. It provides individual channel isolation, overcurrent protection, and HART communication support. Its 10 ms data refresh cycle and 100 ms input step response time define its signal acquisition characteristics for process control applications.\u003c\/p\u003e\n\u003ch3\u003eInput Signal Processing and Channel Isolation\u003c\/h3\u003e\n\u003cp\u003eThe NFAI135 accepts 4 to 20 mA analog signals through eight isolated input channels. Channel isolation separates the electrical input paths, while the specified 500 V AC withstand voltage applies both between input\/output and the system and between individual channels, each for one minute.\u003c\/p\u003e\n\u003cp\u003eThe module provides overcurrent protection and supports an allowable input current of 25 mA. Its input resistance depends on the module power state: 250 ohm when powered on and at least 500 kohm when powered off. This distinction is relevant when checking transmitter loop loading and circuit conditions during power-down.\u003c\/p\u003e\n\u003ch3\u003eHART Communication and Transmitter Supply\u003c\/h3\u003e\n\u003cp\u003eHART communication is supported, allowing compatible field devices to exchange digital information over the analog current loop. The module also provides a transmitter power supply with a specified output range of 20.2 to 29.3 V. The actual loop configuration should account for transmitter requirements, wiring resistance, and the available supply voltage.\u003c\/p\u003e\n\u003ch3\u003eAccuracy and Response Characteristics\u003c\/h3\u003e\n\u003cp\u003eThe specified accuracy is +\/-0.1% of full scale, with a maximum temperature drift of +\/-0.01% per deg C. The 10 ms data refresh cycle describes how frequently input data is updated, while the 100 ms input step response time describes the response to a change in the input signal. These are separate characteristics and should not be treated as interchangeable timing specifications.\u003c\/p\u003e\n\u003ch3\u003eElectrical Characteristics and Power Consumption\u003c\/h3\u003e\n\u003cp\u003eThe module has a maximum current consumption of 360 mA at 5 V DC and 450 mA at 24 V DC. These values should be considered separately when checking the power budget of the I\/O assembly. The specified weight is 0.3 kg.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cfigure\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eNFAI135-S50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBase Model\u003c\/td\u003e\n\u003ctd\u003eNFAI135\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eYokogawa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eAnalog Input Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Input Channels\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChannel Configuration\u003c\/td\u003e\n\u003ctd\u003eIsolated channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Signal\u003c\/td\u003e\n\u003ctd\u003e4 to 20 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAllowable Input Current\u003c\/td\u003e\n\u003ctd\u003e25 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOvercurrent Protection\u003c\/td\u003e\n\u003ctd\u003eProvided\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Resistance (Power ON)\u003c\/td\u003e\n\u003ctd\u003e250 ohm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Resistance (Power OFF)\u003c\/td\u003e\n\u003ctd\u003e500 kohm or more\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAccuracy\u003c\/td\u003e\n\u003ctd\u003e+\/-0.1% of full scale\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eData Refresh Cycle\u003c\/td\u003e\n\u003ctd\u003e10 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Step Response Time\u003c\/td\u003e\n\u003ctd\u003e100 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Drift\u003c\/td\u003e\n\u003ctd\u003eMax. +\/-0.01%\/deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWithstanding Voltage\u003c\/td\u003e\n\u003ctd\u003e500 V AC for 1 minute\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWithstanding Voltage - Input\/Output to System\u003c\/td\u003e\n\u003ctd\u003e500 V AC for 1 minute\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWithstanding Voltage - Channel to Channel\u003c\/td\u003e\n\u003ctd\u003e500 V AC for 1 minute\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmitter Power Supply\u003c\/td\u003e\n\u003ctd\u003e20.2 to 29.3 V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Current Consumption (5 V DC)\u003c\/td\u003e\n\u003ctd\u003e360 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Current Consumption (24 V DC)\u003c\/td\u003e\n\u003ctd\u003e450 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExternal Connection\u003c\/td\u003e\n\u003ctd\u003ePressure clamp terminal, MIL connector cable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.3 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eModel and Suffix Identification\u003c\/h3\u003e\n\u003cp\u003eThe NFAI135 model designation identifies an 8-channel, 4 to 20 mA analog input module with isolated channels. Yokogawa documentation defines the suffix codes as follows:\u003c\/p\u003e\n\u003cfigure\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eCode\u003c\/th\u003e\n\u003cth\u003eDescription\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e-S\u003c\/td\u003e\n\u003ctd\u003eStandard type\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003ctd\u003eWith no explosion protection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e0\u003c\/td\u003e\n\u003ctd\u003eBasic type\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003cp\u003eFor the specified NFAI135-S50, the ordering configuration is standard type, without explosion protection, and basic type. The -S designation should not be confused with the -H version, which is the HART communication configuration.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Does the NFAI135-S50 support HART communication?\u003c\/p\u003e\n\u003cp\u003eA: The -S suffix identifies the standard version. Yokogawa specifies -H for the HART communication version, so HART capability should not be assumed for the NFAI135-S50.\u003c\/p\u003e\n\u003cp\u003eQ: What is the difference between NFAI135 and NFAI141?\u003c\/p\u003e\n\u003cp\u003eA: Both are 4 to 20 mA analog input modules, but the NFAI135 has eight isolated input channels, whereas the NFAI141 has 16 non-isolated input channels. Channel isolation and channel count are important selection criteria.\u003c\/p\u003e\n\u003cp\u003eQ: What should be checked when replacing an NFAI135-S50?\u003c\/p\u003e\n\u003cp\u003eA: Verify the complete model and suffix, input channel configuration, terminal or connector arrangement, and explosion-protection requirements. Also check the installed terminal block and cable configuration before ordering a replacement.\u003c\/p\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":69254171492594,"sku":"NFAI135-S50","price":235.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0730\/5589\/5794\/files\/NFAI135-S50.jpg?v=1794193939","url":"https:\/\/www.petrospare.com\/products\/yokogawa-nfai135-s50-8-channel-isolated-analog-input-module","provider":"Petro Spare Industrial Limited","version":"1.0","type":"link"}