Allen‑Bradley 1756‑L71 ControlLogix 5570 PLC Controller 2MB User Memory

The Allen‑Bradley 1756‑L71 is a ControlLogix 5570 programmable automation controller (PAC) designed for high‑performance industrial control systems. It provides 2 MB of user memory, 0.98 MB of I/O memory, and supports up to 128,000 digital I/O points and 4,000 analog I/O points. Used in ControlLogix automation systems with PLC processors, I/O modules, communication adapters, and chassis backplanes.

Applications:

• Large‑scale process control and automation

• High‑speed data acquisition and complex logic processing

• Integrated motion control in manufacturing systems

• Redundant industrial control environments (full controller redundancy supported)

• OEM equipment and custom machine building

Key Features:

• 2 MB user memory + 0.98 MB I/O memory

• Supports up to 128,000 digital I/O, 4,000 analog I/O

• Built‑in USB port for programming and firmware updates (full‑speed USB 2.0)

• 4‑character alphanumeric display for onboard diagnostics and runtime monitoring

• Supports optional communication adapters: EtherNet/IP, ControlNet, DeviceNet, DH+, Remote I/O, SynchLink, third‑party networks

• Full controller redundancy support (paired with identical controller on same ControlNet network)

Technical Specifications:

• Manufacturer: Allen‑Bradley (Rockwell Automation)

• Model: 1756‑L71

• Series: ControlLogix 5570

• User memory: 2 MB

• I/O memory: 0.98 MB

• Non‑volatile memory: 1 GB SD card (included)

• Maximum digital I/O: 128,000 points

• Maximum analog I/O: 4,000 points

• Number of tasks: 32

• Programs per task: 100

• Built‑in communication: USB port only (optional adapters for network communication)

• Power dissipation: 2.5 W / 8.5 BTU/hr

• Operating temperature: 0‑60°C (32‑140°F)

• Storage temperature: -40‑85°C

• Dimensions (W×H×D), Typical: 1.98 × 7.14 × 4.84 in (50.4 × 181 × 123 mm)

• Weight: 0.45 kg (1.00 lb)

• Enclosure: Open‑style

• UPC: 612598876013

System Integration:

• PLC Architecture: ControlLogix 1756 platform

• Programming Software: Studio 5000 / RSLogix 5000

• Chassis Compatibility: 1756‑A4, ‑A7, ‑A10, ‑A13, ‑A17 ControlLogix chassis

• Communication: USB programming port plus optional EtherNet/IP, ControlNet, DeviceNet, DH+, Remote I/O, SynchLink adapters

• I/O Modules: 1756 digital, analog, motion, and specialty I/O modules

• Power Supply: 1756‑PA72 (AC) or 1756‑PB72 (DC)

• Redundancy: Full controller redundancy support when paired with a second 1756‑L71 on same ControlNet backbone

• Motion Control: Supports SERCOS interface, analog encoder input, LDT input, SSI input, integrated motion over EtherNet/IP

Related Products:

• I/O Modules: 1756‑IB32 Digital Input, 1756‑OB32 Digital Output, 1756‑IF16 Analog Input

• Communication Modules: 1756‑EN2TR EtherNet/IP, 1756‑CN2R ControlNet

• Power Supply: 1756‑PA72 (85‑265V AC), 1756‑PB72 (24V DC)

• Chassis: 1756‑A10 (10‑slot), 1756‑A13 (13‑slot)

• For higher memory capacity: 1756‑L71 to 1756‑L73/L74 memory upgrade pathways

PLC ERA is an independent industrial automation distributor. Products are sourced from established supply channels and inspected before shipment. International shipping available.