{"product_id":"1756-irt8i-allen-bradley-controllogix-8-point-analog-input-module","title":"1756-IRT8I Allen-Bradley ControlLogix 8-Point Analog Input Module","description":"\u003ch3\u003e\u003cstrong\u003eEngineering Architecture\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003e1756-IRT8I\u003c\/strong\u003e module operates as an advanced 8-channel isolated analog input interface engineered for Rockwell Automation \u003cstrong\u003eControlLogix\u003c\/strong\u003e architectures. Utilizing high-resolution Sigma-Delta conversion, this unit processes multi-variable temperature and millivolt signals while maintaining stringent galvanic isolation across complex industrial loops.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTechnical Parameters and Specifications\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"5\" cellspacing=\"0\" style=\"border-collapse: collapse; width: 100%;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eManufacturer \/ Brand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRockwell Automation \/ Allen-Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eProduct Series\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003ca href=\"https:\/\/www.plcsparehub.com\/collections\/allen-bradley-1756-controllogix\"\u003eControlLogix\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModel \/ Catalog Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003e1756-IRT8I\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModule Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eIsolated RTD \/ Thermocouple \/ Millivolt Input\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eInput Channels\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e8 individually isolated channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eResolution\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e24-bit Sigma-Delta conversion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupported RTD Types\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePlatinum (alpha=385\/3916), Nickel (alpha=672\/618), Copper (alpha=427)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupported Thermocouples\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eTypes B, C, D, E, J, K, N, R, S, T, TXK\/XK (ITS-90 linearization)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMillivolt Input Range\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e-100 to 100 mV\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eIsolation Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e250V Continuous isolation rating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBackplane Current Draw\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e250 mA at 5.1V DC, 150 mA at 24V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePower Dissipation\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4.6 Watts maximum (15.7 BTU per hour thermal dissipation)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003cstrong\u003ePhysical Integration and Terminal Configuration\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMount the \u003cstrong\u003e1756-IRT8I\u003c\/strong\u003e module into any standard \u003cstrong\u003eControlLogix\u003c\/strong\u003e chassis slot using aligned backplane guides.\u003c\/li\u003e\n\u003cli\u003eAttach a compatible 36-pin Removable Terminal Block (RTB), specifically the \u003cstrong\u003e1756-TBS6H\u003c\/strong\u003e or \u003cstrong\u003e1756-TBCH\u003c\/strong\u003e housing.\u003c\/li\u003e\n\u003cli\u003eConnect dual local or remote Cold Junction Compensation (CJC) sensors to maintain thermocouple measurement accuracy within +\/- 0.3°C.\u003c\/li\u003e\n\u003cli\u003eEnsure proper wire-off detection configuration during initial software setup to monitor sensor loop continuity.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eAdvanced Diagnostics and Fault Detection Capabilities\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eActive open-circuit detection flags disconnections within 2 seconds for thermocouples and 3-wire RTDs, and 5 seconds for 4-wire RTDs.\u003c\/li\u003e\n\u003cli\u003eBuilt-in rate alarms and process alarms evaluate real-time sensor variations against pre-configured engineering limits.\u003c\/li\u003e\n\u003cli\u003eSynchronized sampling and programmable digital filters suppress 50 Hz and 60 Hz common-mode electrical noise.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Data Pipeline\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eConverts analog measurements into IEEE 32-bit floating point data format for seamless controller consumption.\u003c\/li\u003e\n\u003cli\u003eIntegrates cleanly with supervisory control systems, HMIs, and advanced PID loop calculation blocks.\u003c\/li\u003e\n\u003cli\u003ePerforms automated lead resistance self-calibration on thermocouple channels whenever module power is cycled.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eLogistics and Warranty Terms\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBacked by a robust \u003cstrong\u003e12-month warranty\u003c\/strong\u003e covering mechanical and electrical manufacturing defects.\u003c\/li\u003e\n\u003cli\u003eExpedited international delivery dispatched through \u003cstrong\u003eFedEx\u003c\/strong\u003e, \u003cstrong\u003eUPS\u003c\/strong\u003e, and \u003cstrong\u003eDHL\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eGuaranteed processing and fulfillment within \u003cstrong\u003e24-48 hours\u003c\/strong\u003e from order verification.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eTarget Equipment and Typical Application Scenarios\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eHigh-temperature chemical reactors requiring precise multi-zone thermocouple monitoring.\u003c\/li\u003e\n\u003cli\u003ePower generation turbine skids utilizing distributed Platinum RTDs for bearing temperature tracking.\u003c\/li\u003e\n\u003cli\u003ePharmaceutical sterilization autoclaves demanding high-resolution millivolt and thermal logging.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eGlobal PLC Spare HUB's Insight and Field Experience\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eCommissioning engineers frequently deploy the \u003cstrong\u003e1756-IRT8I\u003c\/strong\u003e when upgrading legacy temperature acquisition loops to high-density ControlLogix architectures. Field experience proves that cycling module power after re-wiring thermocouple inputs is critical to force automatic lead resistance self-calibration. Furthermore, technicians must verify that the 5.1V backplane power budget accommodates the 250 mA current draw of the \u003cstrong\u003e1756-IRT8I\u003c\/strong\u003e before populating fully loaded 1756 chassis.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What selection factors determine whether to use 3-wire versus 4-wire RTD configurations with this module?\u003c\/strong\u003e\u003cbr\u003eA: Choose 4-wire RTD setups for extreme precision environments to completely eliminate lead wire resistance errors over long cable runs, while 3-wire setups suffice for standard industrial distance spans.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Why does the module omit the RTS parameter, and how is sampling rate managed instead?\u003c\/strong\u003e\u003cbr\u003eA: The \u003cstrong\u003e1756-IRT8I\u003c\/strong\u003e derives its channel sampling rate exclusively from the Requested Packet Interval (RPI) configured within the Logix designer environment rather than individual channel sweep timers.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What corrective steps should be taken if an open-circuit fault is falsely triggered on a thermocouple channel?\u003c\/strong\u003e\u003cbr\u003eA: Inspect the 36-pin \u003cstrong\u003e1756-TBS6H\u003c\/strong\u003e terminal block wiring to ensure terminal screws are torqued correctly and verify that CJC sensors are seated firmly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Can thermocouple and RTD sensors be wired concurrently across different channels on the same module?\u003c\/strong\u003e\u003cbr\u003eA: Yes, all 8 channels are individually isolated and configurable in any combination of RTD, thermocouple, or millivolt input modes.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How do digital and notch filters protect temperature readings from plant floor electrical interference?\u003c\/strong\u003e\u003cbr\u003eA: The integrated notch filter provides up to 125 dB of common-mode rejection at 50\/60 Hz, successfully neutralizing high-frequency variable frequency drive noise picked up by unshielded thermocouple extension wires.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45013913206966,"sku":"1756-IRT8I","price":176.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/1756-IRT8I-3.jpg?v=1788938850","url":"https:\/\/www.plcsparehub.com\/products\/1756-irt8i-allen-bradley-controllogix-8-point-analog-input-module","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}