Allen-Bradley 1756-L81ES ControlLogix Processor 3 MB

Name: Allen-Bradley 1756-L81ES ControlLogix Processor
Brand: Allen-Bradley
SKU: 1756-L81ES
Price: 3499.99 USD
Availability: InStock

In stock: 2 units in Milwaukee, WI. Physically stocked and ready to ship or available for local pickup. Includes a 1-year full-function warranty.

3 MB GuardLogix 5580 safety controller · embedded 1 Gb EtherNet/IP port

Allen-Bradley 1756-L81ES GuardLogix 5580 safety controller, 3 MB – Series B (1 of 6)

Actual NJT inventory photos

Price

$3,499.99USD

Unused surplus units available

Request Repair QuoteEstimated $1,440.00

Part Number	1756-L81ES
Description	GuardLogix 5580 safety controller, 3 MB. In stock in unused surplus condition, Series B.
Shipping	Ships same or next business day 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 ($525.00) 3 years +25% of product price ($875.00) View full warranty policy
Returns	90-day free returns. View return policy
Exchange	Send us your defective 1756-L81ES after your purchase for a 10% core credit ($350). We also purchase old or damaged parts outright.

Replacement Options for 1756-L81ES

Pick a condition and series below. UPS Ground shipping included.

Allen-Bradley 1756-L81ES ControlLogix Processor – Series B, New surplus (sealed)

Allen-Bradley 1756-L81ES ControlLogix Processor – Series B, New surplus (sealed), second photo

Allen Bradley 1756-L81ES /B GuardLogix 5580 Safety Controller - Sealed Surplus

$3,499.99 USDIn-stock match

Condition: New surplus (sealed)

Series B

2 in stockView details

Variants

Part NumberConditionSeriesQtyPrice

1756-L81ES /B$3,499.99

New surplus (sealed) · Series B · 2 in stock

1756-L81ES /BNew surplus (sealed)Series B2$3,499.99 USD

1756-L81ES

Refurbished — pick series, then request a quote

Series neededRequest Quote

1756-L81ESRefurbishedSeries needed—Request Quote

Availability

2 units in stock

Repairs

1756-L81ES Mail-In Repair Service

Estimated: $1,440.00

Part Number Decoder

GuardLogix 5580 safety controller

1756L81ES

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 plus 1.5 MB of safety memory.
E: Embedded portEmbedded EtherNet/IP port (1 Gb) on the controller front, so no separate bridge module is required for the first network.
S: SafetyGuardLogix safety controller (SIL 2 / PLd on its own, SIL 3 / PLe with a 1756-L8SP safety partner), adds 1.5 MB of safety memory alongside the standard memory.

Decoded from the Rockwell Automation catalog-number structure. Series and firmware revision are printed on the product label, not encoded here.

Series & Revisions

Series B in stock; other series on request.

Series B controllers run firmware revision 31.011 or later; Series A units also run the earlier 5580 revisions (28 to 30).

Every series needs a Series B or Series C 1756 chassis (Series B derated to 50 °C ambient); 5580 controllers do not work in a Series A chassis.

Series notes: Studio 5000 keys on catalog number and firmware revision, not series. Fitting a Series B into a project on revision 28 to 30 means upgrading the project to 31 or later first.

Intended Use

Intended for plant-wide discrete, process, and motion control applications. ControlLogix controllers run high I/O-count machines, batch and continuous process lines, and coordinated multi-axis motion from a single chassis, with redundancy and plant-network connectivity when the application calls for it. Typical homes are automotive and tire plants, food and beverage lines, water and wastewater, oil and gas skids, and large packaging systems. Safety-rated for use in GuardLogix safety chains up to SIL 3 / PLe.

Physical Data

Weight and DimensionsWeight0.87 lb (0.39 kg)H × W × D5.7 × 1.4 × 5.7 in. (145 × 35 × 145 mm)

Weight	0.39 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 Weight	0.92 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.

Similar Part Numbers

1756-L82ES Memory size: 5 MB of standard user memory plus 2.5 MB of safety memory
1756-L83ES Memory size: 10 MB of standard user memory plus 5 MB of safety memory
1756-L84ES Memory size: 20 MB of standard user memory plus 6 MB of safety memory

Allen Bradley Information

Technical Specifications15 parameters from manufacturer-published specifications

Lifecycle	Active Verify current status with the manufacturer.
Controller family	GuardLogix 5580
Standard memory	3 MB
Safety memory	1.5 MB
Safety rating	Up to SIL 3 / PLe with 1756-L8SP safety partner; SIL 2 / PLd standalone
EtherNet/IP nodes supported	100
Tasks	31 standard tasks + 1 safety task
Embedded communication	1 × EtherNet/IP port, 10/100/1000 Mbps; 1 × USB 2.0
Digital I/O, max	128,000
Analog I/O, max	4,000
Memory card	1784-SD4 (4 GB SD, included)
Energy storage	Embedded energy storage module (no battery)
Motion	Integrated Motion on EtherNet/IP
Backplane current	1.20 A @ 5.1V DC
Power dissipation	6.2 W
Chassis slots	1

Typical manufacturer-published values for this catalog number; confirm against the current manufacturer documentation before specifying.

Can the 1756-L81ES be repaired?

Yes. NJT Automation repairs the 1756-L81ES by mail-in: diagnostic evaluation, component-level repair and a functional test, backed by a 1-year full-function warranty.

NJT managed repair. No evaluation fee; no repair, no charge. Prepaid UPS label both ways, $650 minimum, rush available. 1-year full-function warranty included, 2- and 3-year options.

Get a repair quoteor text photos and symptoms to (414) 331-5954

Compare quotes from independent repair technicians. Post your repair on RepairMode to receive competitive bids from experienced technicians. Each technician sets their own pricing and warranty.

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Common failures

Failure patterns we regularly see on GuardLogix 5580 safety controller hardware like the 1756-L81ES:

Repeated major faults after a firmware flash that did not complete
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

Related services:PLC Repair All Repair Services

Photos by NJT Automation; test videos from NJT or network repair technicians.

Still have questions?

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

Frequently Asked Questions

What is the 1756-L81ES?

The Allen-Bradley 1756-L81ES is a GuardLogix 5580 safety controller: 3 MB GuardLogix 5580 safety controller, embedded 1 Gb EtherNet/IP port.

What condition is it in?

NJT Automation currently has 2 units of the 1756-L81ES in stock in unused surplus condition (Series B). Each listing states its own condition and series. Factory-sealed, unused surplus stock in original packaging. May carry an older date code or series than current OEM production.

How much does it cost?

At NJT Automation, 5 1756-L81ES GuardLogix 5580 safety controllers have sold since 2024 for $2,500 – $3,400, with a median of $2,700. Right now 2 units are in stock at $3,500, depending on condition and series.

When does this part ship?

2 units of the 1756-L81ES GuardLogix 5580 safety controller are on the shelf in Milwaukee, WI, priced from $3,499.99. Orders before 5:00 PM Central on a business day ship the same day; next-day air is available at checkout.

How much memory does it have?

3 MB of standard user memory plus 1.5 MB of safety memory.