1756-L71

Product information

Product Overview

The 1756-L71 is a ControlLogix 5570 controller with 2 MB of user memory. Series B hardware adds a USB local programming port and Secure Digital non-volatile memory support. It has no embedded network port — EtherNet/IP, ControlNet and other networks are added through 1756 communication modules (EN2T, CNB, DNB etc.) in adjacent chassis slots. Rockwell’s official lifecycle status is Active — Mature: still manufactured, but positioned as a mature product with newer 5580 controllers recommended for new designs.

Technical Specifications (Official Rockwell Data)

Product family	ControlLogix 5570 controller
User memory	2 MB
Non-volatile memory	Secure Digital (SD) card
Embedded network port	None — networks via 1756 communication modules
Local programming port	1 × USB (Series B)
Motion axes supported	100
Replacement battery	1756-ESMCAP
Power draw	5 mA @ 1.2 V DC, 800 mA @ 5.1 V DC
Power dissipation (full load)	2.5 W
Product series	Series B
Lifecycle status (Rockwell)	Active – Mature

Lifecycle Status & Availability

Official lifecycle status is Active – Mature: Rockwell continues to supply the 1756-L71, but directs new projects to the ControlLogix 5580 family (L81E/L83E/L85E). Repair options are available. Sites running L71 in production today typically keep a spare in stock and plan the 5580 migration window deliberately, since chassis and I/O carry over unchanged.

Typical Applications

• Installed base of ControlLogix 5570 systems where an identical controller is needed for swap-out
• Compact machines whose program fits 2 MB and whose networks are already served by EN2T/CNB modules
• Spare-part procurement for production lines still standardized on 5570 firmware baselines

Related & Compatible Models

Neighbours in the 5570 ladder: 1756-L72/L73/L74/L75 (2–32 MB variants of the same generation). The discontinued 1756-L61 (5561, 2 MB) is the predecessor with no USB port. Direct successor: 1756-L81E (5580, 3 MB, embedded Gigabit EtherNet/IP) — drop-in compatible with existing chassis and I/O.

Requesting a Quotation

When requesting a quotation for 1756-L71, state the series letter and firmware revision from the label (Series A and B hardware differ in ports), and mention whether the SD card or battery (1756-ESMCAP) is needed with it. Stock and pricing are confirmed per request; mature-status products can see occasional supply gaps, so quantity requirements help us source correctly.

Frequently Asked Questions

Is the 1756-L71 discontinued?

No — Rockwell’s official lifecycle status is Active–Mature. It remains orderable and repairable, but newer ControlLogix 5580 controllers are recommended for new projects. Verify the exact status at order time if your project has a long lead window.

What is the difference between Series A and Series B?

Series B hardware added the USB local programming port and SD-card non-volatile memory support. The series letter is printed on the product label — include it in your quotation request.

Which battery does it use?

The 5570 controller family uses the 1756-ESMCAP energy-storage module as replacement battery option. Add it to the quotation if your spare-parts plan includes it.

Should I migrate to a 1756-L81E?

For new designs, yes — the 5580 platform offers more memory, an embedded Gigabit EtherNet/IP port and current-generation support. For existing lines, chassis/I/O reuse makes migration low-friction; send your current configuration if you want a migration-oriented quotation.

Do I need an Ethernet module with it?

Yes. The L71 has no embedded network port — EtherNet/IP requires a 1756-EN2T (or discontinued ENBT) module in the chassis. This is the main functional difference from the 5580 generation.