The 6ES7954-8LT03 is a 32 GB Flash-EPROM memory card for SIMATIC S7-1200 and S7-1500 controllers. It was the original 32 GB release in the S7-1x00 memory card family and has since been succeeded by the functionally identical 6ES7954-8LT04-0AA0. At 24 × 32 × 2.1 mm and approximately 3 grams, it uses the same compact form factor shared across all S7-1x00 memory cards.

What changed between the 8LT03 and the 8LT04?

Nothing that affects you as the user. Siemens updated the article number from -8LT03 to -8LT04 for internal manufacturing reasons. The two cards share the same 32 GB capacity, 3.3V Flash-EPROM technology, 100,000-cycle minimum write endurance, and physical dimensions. They are drop-in interchangeable — an 8LT04 works in any slot that previously held an 8LT03, and vice versa.

When should I order the 8LT03 instead of the 8LT04?

The 8LT03 is discontinued. Siemens now ships the 8LT04 for all new orders — if you place an order for an 8LT03 today, it will be automatically converted to the 8LT04. The only scenario where you would specifically seek out an 8LT03 is for an exact like-for-like replacement in an existing machine whose bill of materials or validation documentation lists the 8LT03 by part number. For all new projects, order the 6ES7954-8LT04-0AA0.

Frequently Asked Questions

Will the 8LT03 eventually stop being supported?

Siemens lists the 8LT03 as a PM300 active product, meaning it remains fully supported for service and replacement. However, new production has shifted to the 8LT04. There is no announced end-of-life date, but planning new projects around the 8LT04 ensures long-term availability.

Can I read a program stored on an 8LT03 using an 8LT04 in a PG?

Yes. The two cards use identical formatting and file system structure. A programming device or CPU reads both cards the same way.