{"product_id":"1756-l61-rockwell-automation-controllogix-plc-controller","title":"1756-L61 Rockwell Automation ControlLogix PLC Controller","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L61\u003c\/strong\u003e\u003c\/span\u003e is a high-performance programmable automation controller within the Allen-Bradley \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003eControlLogix Series\u003c\/strong\u003e\u003c\/span\u003e by Rockwell Automation. Designed for chassis-based mounting, it provides 2 MB of user program memory and 478 KB of dedicated I\/O memory. The unit manages complex industrial processes with up to 128,000 digital I\/O points and 4,000 analog I\/O points. It features an integrated RS-232 serial interface and supports optional non-volatile memory backup using a 1784-CF128 CompactFlash card.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eTechnical \u0026amp; Hardware Specifications\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eBrand \u0026amp; Manufacturer\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eAllen-Bradley \/ Rockwell Automation\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eModel \u0026amp; Catalog Number\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e\n\u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L61\u003c\/strong\u003e\u003c\/span\u003e (\u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003eControlLogix Series\u003c\/strong\u003e\u003c\/span\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\u003eProgrammable Logic Controller \/ Processor Module\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eUser \u0026amp; I\/O Memory\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e2 MB User Memory; 478 KB I\/O Memory\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eNon-Volatile Memory\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e128 MB max via optional 1784-CF128 CompactFlash Card\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eMaximum Capacity\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e128,000 Digital I\/O; 4,000 Analog I\/O; 250 Controller Connections\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eProgram Execution Speed\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e0.08 milliseconds scan time rate\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\u003e1.2 A at 5.1 Vdc (1200 mA); 14 mA at 24 Vdc\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003ePower \u0026amp; Thermal Dissipation\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e3.5 W power dissipation; 11.9 BTU\/hr thermal output\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eIsolation Voltage\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e30 V continuous isolation; dielectric withstand tested at 720 Vdc for 60 seconds\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eSerial Port Protocols\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eRS-232 supporting DF1 Full\/Half-Duplex, DF1 Radio Modem, DH-485, ASCII, Modbus via logic\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003e\u003cstrong\u003eSystem Architecture \u0026amp; Environmental Limits\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eChassis Compatibility\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eMounts in any slot of 1756-A4, 1756-A7, 1756-A10, 1756-A13, or 1756-A17 chassis\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eSupported Programming\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eRelay Ladder Logic (RLL), Structured Text (ST), Function Block Diagram (FBD), Sequential Function Chart (SFC)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eTask Scheduling Capacity\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e32 multitasking structures; 100 programs per task; supports event-driven triggers\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eBattery Backup Hardware\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eSeries A: 1756-BA1, 1756-BATM, or 1756-BATA; Series B: 1756-BA2 lithium battery\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eOperating \u0026amp; Storage Temp\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003eOperating: 0°C to +60°C (32°F to 140°F); Storage: -40°C to +85°C (-40°F to 185°F)\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003eVibration \u0026amp; Shock Resilience\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e10 to 500 Hz at 2 g peak vibration; 30 g operating shock; 50 g non-operating shock\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003e\u003cstrong\u003ePhysical Mass \u0026amp; Enclosure\u003c\/strong\u003e\u003c\/td\u003e\n      \u003ctd\u003e0.32 kg (0.71 lbs); open-style enclosure construction\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003e\u003cstrong\u003eTarget Applications \u0026amp; Machinery Diagnostics\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L61\u003c\/strong\u003e\u003c\/span\u003e processor handles medium-to-large industrial automation tasks such as high-speed packaging lines, water treatment plants, automotive assembly cells, and material handling systems. Control engineers utilize its multi-tasking execution engine to separate deterministic motion routines from asynchronous network communication tasks. System diagnostic routines monitor real-time battery status, track network connection dropped packets across 250 logical paths, and log controller fault codes directly to non-volatile CompactFlash storage during power loss events.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eGlobal PLC Spare HUB's Insight\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eWhen migrating older production lines from legacy PLC-5 networks, our automation specialists frequently install the \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003eControlLogix Series\u003c\/strong\u003e\u003c\/span\u003e \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L61\u003c\/strong\u003e\u003c\/span\u003e as a centralized communication bridge. By pairing this CPU with a 1756-DHRIO module, engineers maintain existing DH+ drops while establishing high-speed EtherNet\/IP links to modern HMIs. In field deployments, installing a fresh 1756-BA2 battery prior to commissioning prevents static memory loss during extended plant shutdowns.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eModel Selection Comparison \u0026amp; Technical Recommendations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eEvaluate hardware options across the \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003eControlLogix Series\u003c\/strong\u003e\u003c\/span\u003e CPU lineup before selecting spare inventory:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStandard Base Model:\u003c\/strong\u003e The \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L61\u003c\/strong\u003e\u003c\/span\u003e delivers 2 MB user memory and built-in RS-232 serial connectivity for traditional field networks.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eExtended Memory Variant:\u003c\/strong\u003e The \u003ca href=\"https:\/\/www.plcsparehub.com\/products\/1756-l62-allen-bradley-controllogix-processor-module\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L62\u003c\/strong\u003e\u003c\/span\u003e\u003c\/a\u003e expands available user memory to 4 MB for applications requiring larger data logging arrays and additional subroutines.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eSelection Advice:\u003c\/strong\u003e For standard machine sequencing under 1,500 logic steps, the \u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L61\u003c\/strong\u003e\u003c\/span\u003e offers an economical control solution. If your application executes extensive recipe management, complex motion axis trajectories, or expanded safety cross-checking, step up to the \u003ca href=\"https:\/\/www.plcsparehub.com\/products\/1756-l62-allen-bradley-controllogix-processor-module\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan style=\"color: #0056b3;\"\u003e\u003cstrong\u003e1756-L62\u003c\/strong\u003e\u003c\/span\u003e\u003c\/a\u003e to avoid runtime memory exhaustion.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWarranty, Dispatch \u0026amp; Packaging Guarantees\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProduct Condition:\u003c\/strong\u003e 100% Brand New and Original in Factory Sealed Packaging\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWarranty Terms:\u003c\/strong\u003e Fully backed by a 12 Months factory warranty\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOrder Processing Speed:\u003c\/strong\u003e Ships out within 24 to 48 hours following payment confirmation\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGlobal Express Courier:\u003c\/strong\u003e Direct worldwide shipping via FedEx, UPS, and DHL\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions (FAQ)\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What cable is required to connect a PC serial port directly to the front interface of this controller?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA: Use a 1756-CP3 or 1747-CP3 null-modem serial cable with a right-angle connector designed for the controller faceplate.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How does hardware Series A differ from Series B regarding battery backup installation?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA: Series A controllers utilize 1756-BA1, 1756-BATM, or 1756-BATA lithium batteries, whereas Series B units require the 1756-BA2 battery.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Can third-party CompactFlash cards be used for non-volatile memory backup?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA: No, only industrial-grade Allen-Bradley 1784-CF128 cards formatting with proprietary industrial block structures are recognized by the controller firmware.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What happens to controller program logic if the main backplane power fails without an installed battery?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA: Volatile RAM is lost immediately; the controller will boot into an unprogrammed default state unless a non-volatile 1784-CF128 card restores the image.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Is it possible to plug or unplug this CPU module while backplane chassis power is applied?\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eA: Yes, the ControlLogix platform supports RIUP (Removal and Insertion Under Power), though stopping active machine motion prior to removal is strongly recommended.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":45013982838966,"sku":"1756-L61","price":161.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/1756-L61.jpg?v=1785314597","url":"https:\/\/www.plcsparehub.com\/products\/1756-l61-rockwell-automation-controllogix-plc-controller","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}