{"product_id":"allen-bradley-controllogix-1756-of8ih-8-point-isolated-hart-analog-output-module","title":"Allen-Bradley ControlLogix 1756-OF8IH 8-Point Isolated HART Analog Output Module","description":"\u003ch2\u003e\u003cstrong\u003eModule Overview\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OF8IH\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis a high-performance analog output module for the ControlLogix 1756 platform, specifically engineered for precision process control and advanced asset management. It features eight fully isolated differential channels, each equipped with its own dedicated HART (Highway Addressable Remote Transducer) modem. This architecture allows the controller to simultaneously command a 4–20 mA actuator and communicate digitally with \"smart\" field devices to retrieve diagnostics, secondary variables, and configuration data. By providing channel-to-channel isolation, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OF8IH\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eensures that electrical noise or ground loops in one field circuit do not affect the accuracy of the other seven channels.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eDetailed Engineering Specifications\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OF8IH\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eutilizes a 15-bit digital-to-analog converter (DAC) to provide high-resolution control over standard industrial current loops.\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eModule Type:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eControlLogix HART Analog Output\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eNumber of Channels:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e8 Isolated Differential Outputs\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eIntegrated Modem:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e1 HART Modem per channel\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOutput Signal Ranges:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e0 to 20 mA and 4 to 20 mA\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eResolution:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e15-Bit across 24 mA\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eHART Scan Time:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eApproximately 1 second per module (with HART enabled)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOvervoltage Protection:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e±24V DC\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eBackplane Current (5.1V DC):\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e300 mA\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eBackplane Current (24V DC):\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e200 mA\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003ePower Dissipation:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e5.8 Watts\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eThermal Dissipation:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e19.8 BTU\/hr\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eIsolation Voltage:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e250V (Continuous), reinforced insulation type\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOperating Temperature:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e0°C to 60°C (32°F to 140°F)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003ePhysical Weight:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e1.00 lbs (0.45 kg)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eAdvanced HART Functionality\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eUnlike standard analog modules, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OF8IH\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eacts as a bridge between the plant floor and asset management software (such as FactoryTalk AssetCentre). Each channel can pass HART \"Pass-Through\" messages, allowing maintenance personnel to remotely calibrate valve positioners or check the internal health of a transmitter without physical field access. The module supports HART versions 5, 6, and 7, and can be configured to trigger alarms in the Logix5000 controller based on the device status bits returned via the HART protocol.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eInstallation and Hardware Integration\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OF8IH\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis a chassis-based module compatible with any standard 1756 ControlLogix rack. It requires a Removable Terminal Block (RTB) for field wiring, with the following models being the most common:\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e1756-TBNH:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e20-position NEMA screw terminal block.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e1756-TBSH:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e20-position spring-clamp terminal block for high-vibration applications.\u003c\/p\u003e\n\u003cp\u003eThe module supports \"Removal and Insertion Under Power\" (RIUP), allowing for hardware replacement without disrupting the power to the rest of the chassis or the communication on the backplane.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eTechnical FAQ\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need a separate HART multiplexer to use this module?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OF8IH\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ehas an integrated HART modem for every channel. The HART digital data is superimposed on the 4–20 mA signal and processed directly by the module hardware.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use this module for 0–10V voltage signals?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OF8IH\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis strictly a current-output module (0–20 mA \/ 4–20 mA). If your application requires voltage outputs, you should consider the 1756-OF8 or a similar voltage-capable module.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the benefit of channel-to-channel isolation?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIn many industrial plants, different field devices may be powered by different sources or have different ground potentials. Isolation prevents current from flowing between these different grounds, which would otherwise cause signal inaccuracies or hardware damage.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":52457807380789,"sku":"1756-OF8IH","price":66.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0973\/7630\/5461\/files\/1756-OF8I_7f497186-fe4d-43af-ae84-1837e5d370b1.jpg?v=1773992843","url":"https:\/\/www.5gplc.com\/products\/allen-bradley-controllogix-1756-of8ih-8-point-isolated-hart-analog-output-module","provider":"High Five PLC Solution Limited","version":"1.0","type":"link"}