{"product_id":"allen-bradley-1746-nr8-analog-input-modules","title":"Allen-Bradley 1746-NR8 Analog Input Modules","description":"\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1746-NR8\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003e1746-NR8\u003c\/strong\u003e RTD\/Resistance Analog Input Module, operates as a dedicated hardware component for temperature and direct resistance signal acquisition within SLC 500 chassis assemblies.\u003c\/p\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eAllen-Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e1746-NR8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.31 kg (0.69 lbs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003eSingle-slot SLC 500 chassis footprint\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e0 to 60 deg C (32 to 140 deg F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e1.82 W maximum (0.5 W at 5 VDC, 1.32 W at 24 VDC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Inputs\u003c\/td\u003e\n\u003ctd\u003e8 channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSupported RTD Sensors\u003c\/td\u003e\n\u003ctd\u003ePlatinum 100\/200\/500\/1000 (385 \u0026amp; 3816), Copper 10 (426), Nickel 120 (618 \u0026amp; 672), Nickel-Iron 604 (518)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResistance Input Ranges\u003c\/td\u003e\n\u003ctd\u003e0 to 150 Ohms, 0 to 300 Ohms, 0 to 500 Ohms, 0 to 1000 Ohms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eA\/D Conversion\u003c\/td\u003e\n\u003ctd\u003eSigma-delta modulation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Resolution\u003c\/td\u003e\n\u003ctd\u003e0.01 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStep Response\u003c\/td\u003e\n\u003ctd\u003e60 ms in, 2.5 ms out\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChannel Update Time\u003c\/td\u003e\n\u003ctd\u003e6 ms to 2 s (dependent on channel configuration)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Current\u003c\/td\u003e\n\u003ctd\u003e100 mA at 5 VDC, 55 mA at 24 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStorage Temperature\u003c\/td\u003e\n\u003ctd\u003e-40 to 85 deg C (-40 to 185 deg F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule Location\u003c\/td\u003e\n\u003ctd\u003eAny chassis slot except Slot 0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eDeterministic Backplane \u0026amp; I\/O Density Scaling\u003c\/h3\u003e\n\u003cp\u003eThe 1746-NR8 digitizes RTD and direct resistance field signals using high-resolution sigma-delta modulation, transmitting analog values directly to the host CPU data table over the SLC backplane bus. The module leverages internal firmware flash compatibility to support configurable channel updating, dynamic sensor linearization, and diagnostic filtering down to 0.01 deg C resolution. Backplane bus communication velocity allows simultaneous 8-channel acquisition across multiple local chassis expansion racks without degrading deterministic scan execution.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Can the 1746-NR8 module be installed in Slot 0 of an SLC 500 chassis?\u003c\/p\u003e\n\u003cp\u003eA: No, Slot 0 is strictly reserved for the SLC 500 system CPU processor module. The 1746-NR8 may be installed in any other available expansion slot within the local chassis.\u003c\/p\u003e\n\u003cp\u003eQ: How does wiring selection impact measurement accuracy when using 2-wire RTDs on the 1746-NR8?\u003c\/p\u003e\n\u003cp\u003eA: 2-wire RTD configurations include line lead resistance in the measurement circuit, which degrades accuracy over long cable runs. Using lower gauge wire (e.g., AWG 16 instead of AWG 24) or switching to 3-wire\/4-wire RTD sensors mitigates line resistance errors.\u003c\/p\u003e\n\u003cp\u003eQ: What power sources are required to operate the 1746-NR8 RTD input module?\u003c\/p\u003e\n\u003cp\u003eA: The module requires no external power supply; all internal operating power is drawn directly from the SLC chassis backplane power supply (100 mA at 5 VDC and 55 mA at 24 VDC).\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eVerify that all system power sources supplying the SLC 500 chassis are turned off before inserting or removing the 1746-NR8 module from the backplane. Ensure the chassis slot keying corresponds to the analog module module type to avoid backplane pin damage.\u003c\/p\u003e\n\u003cp\u003eConnect 2-wire RTD field devices using Belden 9501 shielded cable or equivalent. For 3-wire and 4-wire RTDs, utilize Belden 9533 or Belden 83503 shielded cable. Terminate cable shielding drain wires strictly at a single enclosure earth ground point to prevent ground loops. Observe that each screw terminal on the Removable Terminal Block (RTB) accepts only a single wire termination to maintain mechanical clamping force and low-impedance electrical contact.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":48791574282430,"sku":"1746-NR8","price":96.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0725\/1145\/5422\/files\/1746-NIO4V_032352ca-fa1b-4182-ba9d-379e4553afe0.png?v=1787819239","url":"https:\/\/www.autooiltech.com\/ar\/products\/allen-bradley-1746-nr8-analog-input-modules","provider":"AutoOilTech Limited","version":"1.0","type":"link"}