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Allen-Bradley 1756-L81E ControlLogix – Ready to Ship / Pick Up

In stock: 1756-L81E 3 MB ControlLogix 5580 controller, embedded 1 Gb EtherNet/IP port. NJT Automation has 4 units available in Milwaukee, WI, ready to ship or available for local pickup. Includes a one-year full-function warranty.

Allen-Bradley 1756-L81E ControlLogix 5580 controller, 3 MB – front view

$2,499.99 – $3,499.99USD

Request Repair QuoteEstimated $1,440.00
Part Number1756-L81E
DescriptionControlLogix 5580 controller, 3 MB. In stock in refurbished and unused surplus condition, Series B.
Shipping
Ships today UPS Ground included | Next-Day Air and Worldwide Shipping available at checkout
Pickup
Free local pickup at 2122 N Prospect Ave. Call ahead at (414) 331-5954.
Warranty
1-year full-function warranty provided by NJT Automation.
Warranty details
Included
1 year, full-function
2 years
+15% of product price (from $375.00)
3 years
+25% of product price (from $625.00)
View full warranty policy
Returns
90-day free returns. View return policy
Exchange

Send us your defective 1756-L81E after your purchase for a 10% core credit ($250 – $350). We also purchase old or damaged parts outright.

Replacement Options for 1756-L81E

In stock and ready to ship today

Allen Bradley 1756-L81E Ser B ControlLogix 5580 Controller 3MB Memory 1756L81E

$2,499.99 USDIn-stock match

Condition: Refurbished

Series B

1 in stock

View Product
Availability
Multiple Options Available
Variants
Part NumberConditionSeriesQtyPrice
1756-L81E /BRefurbishedSeries B1$2,499.99 USD1756-L81E /BUnused surplus (new old stock)Series B1$3,249.99 USD1756-L81ES /BUnused surplus (new old stock)Series B2$3,499.99 USD
1756-L81ERefurbished—Request Quote
Repairs

1756-L81E Mail-In Repair Service

Estimated: $1,440.00

Part Number Decoder

ControlLogix 5580 controller
1756L81E

3 MB ControlLogix 5580 controller, embedded 1 Gb EtherNet/IP port.

1756
BulletinControlLogix: Rockwell Automation's chassis-based control platform (controllers, I/O, communication modules, power supplies and chassis).
L
Module typeLogix controller (CPU module).
8
GenerationControlLogix 5580: Logix5580 series (embedded 1 Gb EtherNet/IP port, 5–20x the performance of 5570).
1
Memory size3 MB of standard user memory.
E
Embedded portEmbedded EtherNet/IP port (1 Gb) on the controller front, so no separate bridge module is required for the first network.
Decoded from the Rockwell Automation catalog-number structure. Series and firmware revision are printed on the product label, not encoded here.

Physical Data

Weight and DimensionsWeight0.87 lb (0.39 kg)H × W × D5.7 × 1.4 × 5.7 in. (145 × 35 × 145 mm)
Weight0.39 kg (0.87 lb)
Typical unit weight
Dimensions (H × W × D)145 × 35 × 145 mm (5.7 × 1.4 × 5.7 in.)
Single-slot controller module
Shipping Weight0.92 kg (2.03 lb)
Estimated: unit weight plus box and packing material; bills as 3 lb
Shipping Box (L × W × H)12 × 12 × 8 in. (305 × 305 × 203 mm)
Smallest standard box fitting the product with 3 in. cushioning per side
Product weight and dimensions are typical manufacturer-published values and may differ by series or option. Shipping box and weight are estimates for freight planning; the packed unit may ship in a different box.

Datasheet

Datasheet available for download
Generated from product specifications; not an official Allen-Bradley datasheet. For an official datasheet, contact Allen-Bradley or an authorized distributor.

Similar Part Numbers

  • 1756-L82E Memory size: 5 MB of standard user memory
  • 1756-L83E Memory size: 10 MB of standard user memory
  • 1756-L84E Memory size: 20 MB of standard user memory

Allen Bradley Information

Technical Description
3 MB ControlLogix 5580 controller, embedded 1 Gb EtherNet/IP port.
Lifecycle: Active. Verify current status with the manufacturer.
Technical Specifications15 parameters from manufacturer-published specifications
Controller familyControlLogix 5580
User memory3 MB
EtherNet/IP nodes supported100 (Logix Designer v30 or later)
Tasks / programs32 tasks; 1,000 programs per task
Embedded communication1 × EtherNet/IP port, 10/100/1000 Mbps; 1 × USB 2.0
Digital I/O, max128,000
Analog I/O, max4,000
Memory card1784-SD4 (4 GB SD, included)
Energy storageEmbedded energy storage module (no battery)
MotionIntegrated Motion on EtherNet/IP
RedundancySupported (Logix Designer v33 or later)
Programming languagesRelay ladder, structured text, function block, sequential function chart
Backplane current1.20 A @ 5.1V DC
Power dissipation6.2 W
Chassis slots1
Typical manufacturer-published values for this catalog number; confirm against the current manufacturer documentation before specifying.

Alternate Part Numbers

1756L81E
CategoryControlLogix
UPC / GTIN887172361326
Part Number1756-L81E
ManufacturerAllen-Bradley
Previously sold 1756-L81E9 sold

NJT Automation has supplied and shipped 9 1756-L81E ControlLogix 5580 controllers since 2024; these listings are sold and the in-stock options above are ready to ship.

Sold
9 since 2024
Price range
$2,200 – $3,400, median $2,700
By condition
Unused surplus (7)$2,200 – $3,400Used (2)$2,500 – $2,650
Series
B × 9

Typical sold price for a 1756-L81E: used around $2,575 and unused surplus around $2,700.

Allen-Bradley 1756-L81E Unused surplus (new old stock) - previously sold by NJT AutomationSold

2020 Allen Bradley 1756-L81E Ser B ControlLogix 5580 Controller - Sealed Surplus

$3,299.99 USD

Unused surplus (new old stock)

Request Quote
14 sold on eBay

Can the 1756-L81E be repaired?

Yes. NJT Automation offers mail-in repair for the 1756-L81E, including diagnostic evaluation, component-level repair, and functional testing.

NJT Managed Repair

One vendor. One warranty. NJT manages the entire process.

  • 1-year full-function NJT warranty, with 2- and 3-year options available
  • Rush service available for production-critical repairs
  • No evaluation or diagnostic charges
  • No repair, no charge
  • "Unrepairable" is not an option
  • Pre-paid UPS shipping label provided for sending your unit in
  • $650 minimum repair charge, shipping included both ways
Get an NJT Repair Quote

Looking for another option? For lower-cost repairs or if you prefer to work directly with an independent repair specialist, compare bids through RepairMode. RepairMode providers operate independently and set their own pricing and warranty terms.

See completed 1756-L81E repairson RepairMode.com ↗

Common 1756-L81E failures

Failure patterns we regularly see on ControlLogix 5580 controller hardware like the 1756-L81E:

  • Controller will not boot or shows a solid red OK LED (nonrecoverable major fault) after a power event
  • SD card corruption: controller reports a load failure or comes up with no project
  • Front USB and 1-Gb Ethernet port failures from ESD or a damaged connector
  • Four-character status display stuck, blank or showing scrolling fault text
  • Overheating in a full chassis, especially with no spacing in sealed enclosures

Repair or replace?

ReplaceReplace the 1756-L81E if it will not boot, shows a solid red fault light, or has lost its program. Another ControlLogix 5580 controller takes the same program: download it, match the firmware, and the line is running again. Order the exact 1756-L81E. The catalog number sets the 3 MB memory, and a different suffix changes it. We have the 1756-L81E in stock. Order before 5:00 PM Central and it ships the same day.
RepairRepair the 1756-L81E when the fault is in the power section, a port or the status display rather than the processor core, or when the controller carries a firmware revision or validated project you cannot easily re-flash onto a different unit. The two 1756-L81E symptoms we see most often are “SD card corruption” and “Front USB and 1-Gb Ethernet port failures”. If a replacement is already installed, repairing the failed 1756-L81E gives you a tested spare on the shelf for the next failure. Our estimated $1,440.00 repair of the 1756-L81E includes full-function testing and a 1-year warranty.

Documented failure modes

Commonly reported issues for the Allen-Bradley 1756-L81E include Energy storage fault, based on recent completed repairs. These are compiled from customer issue descriptions and technician repair notes. A technician confirms the actual root cause of each unit during evaluation.

Request a Repair Quote

Text photos of the faulty unit and the symptoms to (414) 331-5954.

Start Your Repair Today

All product photos were taken by NJT Automation. Test videos originated from either NJT Automation internally or from repair technicians within our network.

Still have questions?

Find answers to shipping, warranties, repairs, and more.

The Allen-Bradley 1756-L81E is a 3 MB ControlLogix 5580 controller, embedded 1 Gb EtherNet/IP port.
NJT Automation currently has 4 units of the 1756-L81E in stock in refurbished and unused surplus condition (Series B). Each listing states its own condition and series. We can quote this part in unused surplus, refurbished, or used condition depending on availability and your preference. Specify your requirement in the RFQ.
At NJT Automation, 9 1756-L81E ControlLogix 5580 controllers have sold since 2024 for $2,200 – $3,400, with a median of $2,700. By condition, used ControlLogix 5580 controllers went for $2,500 – $2,650 and unused surplus ControlLogix 5580 controllers went for $2,200 – $3,400. Right now 4 units are in stock at $2,500 to $3,500, depending on condition and series.
NJT Automation has 4 units of the 1756-L81E ControlLogix 5580 controller on the shelf in Milwaukee, WI, priced from $2,499.99 to $3,499.99. Orders placed before 5:00 PM Central on business days ship the same day; orders placed after the cutoff ship the next business day.
Yes. UPS Next Day Air is available at checkout for the 1756-L81E ControlLogix 5580 controller. Place your order before 5:00 PM Central on a business day and your in-stock item ships the same day for next-business-day delivery.
Yes. Free local pickup is available for the 4 in-stock 1756-L81E units at NJT Automation, 2122 N Prospect Ave, Milwaukee, WI, during business hours. Contact us to arrange a pickup time.
3 MB of standard user memory.
Disclaimer

Trademarks & Compatibility

All trademarks, service marks, trade names, brand names, and logos displayed on this website are the property of their respective owners. Any references to manufacturers, products, or brands are for identification and compatibility purposes only and do not imply any affiliation with, endorsement by, sponsorship from, or authorization by the respective trademark owners.

Independent Supplier

NJT Automation is an independent supplier of surplus, refurbished, and pre-owned industrial automation equipment. Unless expressly stated otherwise, NJT Automation is not an authorized distributor, dealer, representative, or affiliate of the original equipment manufacturer (OEM) for any products offered on this website.

Product Condition & Warranty

Products sold by NJT Automation may be surplus inventory, discontinued models, older series, or units with earlier manufacturing date codes than those currently available from the OEM or its authorized distribution network. As NJT Automation is not an authorized distributor, manufacturer warranties, support programs, and other OEM services may not apply. Any warranty provided is solely that of NJT Automation, where applicable.

Firmware & Software Licensing

Certain programmable logic controllers (PLCs), drives, HMIs, and other electronic products may require firmware to operate. While some products may include firmware, NJT Automation makes no representations or warranties regarding whether firmware is installed, the firmware version or revision level, its compatibility with your application, or its licensing status.

NJT Automation does not provide, obtain, transfer, or license firmware on behalf of customers. We make no representation regarding your ability or legal right to obtain, download, install, or use firmware from the OEM, its authorized distributors, or any other source. It is the customer's sole responsibility to ensure compliance with all applicable End User License Agreements (EULAs), software licenses, intellectual property rights, and other terms governing the acquisition, installation, and use of firmware.