{"product_id":"allen-bradley-1756-ow16i-controllogix-16-point-digital-relay-module","title":"Allen-Bradley 1756-OW16I ControlLogix 16 Point Digital Relay Module","description":"\u003ch3\u003eTechnical Overview\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-OW16I\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003eoperates as a high-integrity, single-slot digital contact output assembly designed for the Allen-Bradley ControlLogix architecture. Engineered specifically for complex process interlocks in thermal power plants, oil refining tank farms, and heavy mining infrastructure, this module provides sixteen independent, Form A normally open relay contact channels. Each output circuit features complete galvanic isolation from adjacent channels and backplane logic, allowing distinct AC and DC field voltages to operate simultaneously on a single module housing. By eliminating common ground reference pathways and suppressing high-voltage transient cross-talk, this module avoids cascaded channel failures, effectively reducing unexpected field instrumentation downtime in high-vibration and electrically noisy industrial processing environments.\u003c\/p\u003e\n\u003ch3\u003eSystem Architecture and Functional Features\u003c\/h3\u003e\n\u003cp\u003eThe hardware topology of this digital relay assembly utilizes sixteen discrete, mechanically robust contact relays configured with basic insulation barriers rated for continuous 250 V electrical isolation. It provides native scheduling capabilities, enabling synchronization of contact state transitions within 16.7 ms maximum with reference to the Coordinated System Time (CST) matrix of the Logix backplane. The module features independent, software-configurable state management for both Fault Mode and Program Mode, allowing system engineers to predefine individual channel responses—Hold Last State, Forced On, or Forced Off (default)—to preserve safe field conditions during processor disruption. It requires no internal hardware jumpers, relying instead on electronic software keying via the integrated development environment to prevent erroneous module cross-insertion during field maintenance.\u003c\/p\u003e\n\u003ch3\u003eEngineering Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003ctd\u003e\u003cstrong\u003eSpecification Metric\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eVerified Technical Data\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1756-OW16I\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eAllen-Bradley\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eSeries\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eControlLogix Digital I\/O\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOutput Type\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eRelay Contacts (16 Form A Normally Open, Individually Isolated)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOperating Voltage Window\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e5 to 125 VDC \/ 10 to 240 VAC (50\/60 Hz)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eCurrent Draw from Backplane\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e150 mA @ 5.1 VDC and 150 mA @ 24 VDC\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eTotal Backplane Power Consumption\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e4.4 W\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003ePower Dissipation (Max)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e4.5 W @ 60 deg C (140 deg F)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eThermal Dissipation Loading\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e15.35 BTU\/hour\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eContinuous Contact Ratings (DC)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 A @ 5-30 VDC, 0.5 A @ 48 VDC, 0.22 A @ 125 VDC\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eContinuous Contact Ratings (AC)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1.5 A @ 120 VAC, 0.75 A @ 240 VAC (50\/60 Hz)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003ePilot Duty Classifications\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eC300, R150\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eMinimum Contact Load Current\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e10 mA\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eInitial Contact Resistance (Max)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e100 mOhm @ 6 VDC, 1 A\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOff-State Leakage Current (Max)\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1.5 mA per point\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eContact Switching Delays\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eOff to On: 10 ms max \/ On to Off: 10 ms max\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eMaximum Switching Frequency\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 operation per 3 seconds (0.3 Hz at rated load)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eIsolation Voltage Stability\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e250 V continuous (basic insulation type), outputs-to-backplane and output-to-output\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eCompatible Removable Terminal Blocks\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1756-TBCH, 1756-TBNH, 1756-TBSH, 1756-TBS6H\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOperating Temperature Range\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0 to 60 deg C (32 to 140 deg F)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eShock Tolerance\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eOperating: 30 G \/ Non-operating: 50 G\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eVibration Resistance\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e2 G @ 10 to 500 Hz\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eNorth American Temp Code\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eT4A\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0.30 kg (0.66 lbs)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eStandard single-slot ControlLogix module envelope\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOrigin\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eUSA\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eFAQs\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the significance of the 10 mA minimum load current specification on the 1756-OW16I?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe electromagnetic contacts require a minimum wetting current of 10 mA to reliably pierce thin film oxidation layers that naturally develop on the contact surfaces over time. Operating below this current threshold can result in erratic signal continuity or false open-circuit indications despite the relay coil being energized.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the 1756-OW16I contain internal fused protection to isolate shorted field loads?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The module is not internally fused. To protect the relay contact pathways from overcurrent damage due to field faults, external fusing must be applied. Utilizing a fused Interface Module (IFM) matching publication 1492-TD008 is recommended, though agency certifications are restricted to direct connections via standard ControlLogix Removable Terminal Blocks (RTBs).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is the maximum switching frequency limited to 0.3 Hz at rated load?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBecause the 1756-OW16I relies on mechanical contacts rather than solid-state triacs or transistors, excessive cycle speeds induce thermal stresses and arc degradation. Restricting the cycle rate to 1 operation per 3 seconds prevents contact overheating and ensures the expected contact lifespan of 300 kHz for resistive loads and 100 kHz for inductive loads.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eField Commissioning and Safety Declarations\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eArc Mitigation for Inductive Loads:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eWhen controlling inductive field elements such as motor starter coils or high-capacity solenoids, external surge suppressors must be installed directly across the load terminals. Use an appropriate RC snubber circuit for AC loops and a freewheeling diode for DC loops. Unsuppressed inductive counter-electromotive force (back-EMF) will accelerate contact degradation, resulting in contact welding and catastrophic module damage.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eTerminal Assembly Selection and Grounding:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eField conductor hookups must be handled using official 36-pin or 20-pin RTBs (e.g., 1756-TBCH, 1756-TBNH). Separate all high-voltage AC current lines from low-voltage DC logic wires by routing them through independent wire ways within the marshalling panel. Ensure the chassis frame maintains a low-impedance connection to the central plant earth ground plane.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eLive Maintenance Warning (RIUP Restrictions):\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAlthough the underlying ControlLogix architecture allows Removal and Insertion Under Power (RIUP) during operational maintenance, executing this process in hazardous locations (Class I Division 2, Temp Code T4A) is dangerous. Field-side supply circuits must be completely isolated and checked for zero voltage before detaching the mechanical terminal blocks or pulling the module from the chassis.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":52695172284779,"sku":"Allen Bradley 1756-OW16I","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0953\/3227\/0443\/files\/allen-bradley-1756-ow16i-controllogix-16do-isolated-relay-module-5cybh5hxcys_028c8623-e0aa-48df-8386-62d2fb3f4c66.jpg?v=1766114081","url":"https:\/\/www.plcprotech.com\/products\/allen-bradley-1756-ow16i-controllogix-16-point-digital-relay-module","provider":"PLC ProTech Ltd.","version":"1.0","type":"link"}