Allen-Bradley 1769-L24ER-QBFC1B​ CompactLogix 5370 L2 Controller – 750 KB, 16 DI / 16 DO, 4 AI / 2 AO, Dual Ethernet, Conformal Coated

Technical Specifications

Main Features and Advantages

Rich Embedded Mixed I/O Reduces Component CountThe standout of the 1769-L24ER-QBFC1B​ versus a bare processor + separate I/O modules is the all-in-one I/O load: 16 DI + 16 DO handles the typical discrete machine skeleton (start/stop, guard interlocks, solenoid banks, indicator stacks), while the 4-universal-AI + 2-AO channels absorb the analog layer—pressure transducers, temperature transmitters, speed potentiometers, analog-drive references—without populating a single 1769 expansion slot. For an OEM building a mid-complexity packaging head or a batch-mixer skid, the 1769-L24ER-QBFC1B​ can often close the I/O spec with zero expansion modules, leaving the 4-slot allowance for specialty items (DeviceNet, thermocouple, ASCII) only if needed.Dual Ethernet with DLR — No External Switch for Small RingsBoth EtherNet/IP ports integrate a 2-port switch on the 1769-L24ER-QBFC1B, enabling Device-Level Ring topology without buying a managed switch. For a machine with a local PanelView Plus HMI and a VFD or two on the same ring, the 1769-L24ER-QBFC1B​ closes the ring itself: port A → HMI → VFD → port B. That’s a bill-of-materials win on every panel where a $300 unmanaged switch used to live. The 8 EtherNet/IP node limit on the L2 family is adequate for typical standalone machines; larger node counts push toward L27ERM or 5380.Conformal Coating for Harsh-Environment DeploymentsThe “F” in QBFC1B is the differentiator: the 1769-L24ER-QBFC1B​ ships with PCB conformal coating, whereas the 1769-L24ER-QB1B​ does not. In washdown zones (food & beverage bottling, dairy CIP skids), humid pulp & paper areas, or outdoor water/wastewater kiosks where condensation cycles are routine, the 1769-L24ER-QBFC1B​ earns its premium over the non-coated SKU. Combined with the ATEX/IECEx/Class I Div 2 listings, the 1769-L24ER-QBFC1B​ clears most hazardous-area paperwork for oil & gas, grain handling, and chemical batch without extra enclosure conditioning.4-Channel HSC Without Extra HardwareMany compact PLCs push high-speed counting to a $400+ add-on card; the 1769-L24ER-QBFC1B​ bakes in a 4-channel, 100 kHz HSC block sharing the embedded DI pool. This covers encoder-based registration on form-fill-seal machines, flow-turbine pulse counting on dosing skids, and parts-per-minute tallies on conveyor lines—again protecting the 4 expansion slots for non-counter duties.Studio 5000 Ecosystem & CIP SecurityRunning on the same Studio 5000 Logix Designer codebase as ControlLogix and the 5380 CompactLogix, the 1769-L24ER-QBFC1B​ inherits the full Logix instruction set, Add-On Instructions (AOIs), and PlantPAx library compatibility. CIP Security is supported on the EtherNet/IP stack, letting integrators enforce encrypted authentication between the 1769-L24ER-QBFC1B​ and upper-tier SCADA or remote-access gateways—a growing requirement in water utilities and pharma where audit trails demand secure-by-default device comms.MRO & Sustainment PositioningWith Rockwell marking the 5370 L2 line as “Mature” and pointing new designs to the 5069/5380 Gen3, the 1769-L24ER-QBFC1B​ has become an MRO-focused SKU: existing L24ER installs in packaging, converting, and material-handling worldwide need sparing, and the conformal-coated “F” version is the one specified for washdown retrofits replacing corroded non-coated units. The 1 GB SD card ships in-box, and firmware (currently v38.xx for the 1769-L2 family) remains downloadable from Rockwell, so the 1769-L24ER-QBFC1B​ is a low-risk sustainment buy even as the platform ages.