1756-L71 | Allen-Bradley | ControlLogix 5570 Programmable Automation Controller

Product Overview

The Allen-Bradley 1756-L71 functions as a high-performance central processing unit within the ControlLogix 5570 family. This controller manages complex automation tasks, including high-speed discrete I/O, advanced process control, and multi-axis integrated motion. It features 2 MB of user memory and ships with 1 GB of non-volatile storage to protect critical application data. We supply this unit in 100% Brand New and Original condition, providing the high-speed execution and expanded I/O capacity required for modern smart manufacturing and heavy industrial applications.

Technical Specifications

Engineering Advantages

The 1756-L71 overcomes the limitations of legacy PLCs by providing a multi-disciplinary control engine designed for high-availability environments:

• High-Speed Logic Execution: The 5570 series architecture significantly reduces scan times compared to previous generations. This enables the controller to manage up to 32 simultaneous tasks, ensuring high-priority event triggers receive immediate processing in high-speed packaging or assembly lines.

• Full Redundancy Support: The module supports bumpless redundancy. When paired with a 1756-RM2 redundancy module, the 1756-L71 ensures continuous process operation. If the primary controller fails, the secondary unit assumes control instantaneously without interrupting field I/O or motion trajectories.

• Expanded Integrated Motion: This processor manages complex motion profiles across EtherNet/IP, SERCOS, or analog interfaces. It synchronizes encoders, LDT inputs, and SSI inputs directly, removing the need for separate motion controllers and simplifying the software architecture in Studio 5000.

• Robust Data Integrity: The included 1 GB non-volatile memory card stores the project permanently. This prevents data loss during extended power outages and allows for rapid "no-laptop" replacement in the field by simply transferring the SD card to a new module.

• Optimized Thermal Management: Drawing only 800 mA at 5.1V, the 1756-L71 produces minimal heat (8.5 BTU per hour). This low thermal footprint allows for high-density chassis configurations without exceeding cabinet temperature limits or requiring external cooling fans.

FAQs

• Does the 1756-L71 require a battery for memory backup?

  No. The 1756-L71 utilizes an energy storage module (ESM) to provide power during shutdown, which allows the controller to write the user program to the non-volatile SD card. This eliminates the maintenance requirements and environmental concerns associated with lithium batteries.

• How do I ensure the "Brand New" condition of the unit?

  We guarantee every 1756-L71 arrives in its original Allen-Bradley factory box with intact security seals. Every processor carries a unique UPC (612598876013) and serial number, ensuring the hardware has zero prior runtime or firmware tampering.

• Which communication networks can the 1756-L71 manage?

  While it features a built-in USB port for local diagnostics, you expand its connectivity via chassis-based adapters. The L71 supports all major industrial protocols, including EtherNet/IP, ControlNet, DeviceNet, Data Highway Plus (DH+), and Remote I/O.

• What is the difference between the 1756-L71 and the L72 or L73?

  The primary difference lies in the user memory capacity. The 1756-L71 provides 2 MB of user memory, which suits medium-scale applications. For larger projects requiring more extensive tag databases or code, you may consider the L72 (4 MB) or L73 (8 MB).