6ES7952-1AL00-0AA0 SIMATIC S7 Memory Card

SKU: 6ES7952-1AL00-0AA0 Category: PLC

Description
Additional information

The Siemens SIMATIC S7 6ES7952-1AL00-0AA0 is a Flash memory card (RAM/EPROM module) designed for use with SIMATIC S7-300 programmable logic controllers. It belongs to the SIMATIC S7 memory card series and serves as a load memory module for storing user programs, data blocks, and configuration data. The card plugs directly into the memory card slot of compatible S7-300 CPUs, providing non-volatile program storage.

The 6ES7952-1AL00-0AA0 is a Flash EPROM card with a storage capacity of 4 MB, allowing retention of user programs and data without battery backup. The card uses Flash technology, meaning data is retained even when power is removed, eliminating the dependency on a backup battery for program retention. It is compatible with a wide range of S7-300 CPU modules and supports standard STEP 7 programming software for program download and memory management. The rugged design ensures reliable operation in industrial environments with vibration and temperature variations.

This memory card is used in manufacturing automation, process control, and machine tool applications where S7-300 PLCs are deployed. It is particularly suited for installations where battery-free program retention is required, such as remote or unmanned control panels. Industries including automotive, food and beverage, chemical processing, and general factory automation rely on this card to ensure program integrity across power cycles and maintenance intervals.

Technical Specifications

Memory Type	Flash EPROM
Storage Capacity	4 MB
Series/Product Family	SIMATIC S7-300
Compatible CPUs	S7-300 CPUs with memory card slot
Data Retention	Battery-free (non-volatile Flash)
Form Factor	SIMATIC S7 memory card module
Operating Temperature	0 °C to +60 °C
Storage Temperature	-40 °C to +85 °C
Relative Humidity	15 % to 95 % (non-condensing)
Certifications	CE, UL
Programming Software	SIMATIC STEP 7

Common Diagnostic Codes

Fault Code 1: Memory card not recognized by CPU — card may be incorrectly inserted or incompatible with the CPU firmware version.
Remove and re-insert the memory card firmly. Verify the card is compatible with the installed CPU firmware version. Try the card in another compatible CPU to isolate the fault.
Fault Code 2: Memory card write error — an error occurred during program download to the Flash memory card.
Retry the download via STEP 7. If the error persists, the card may have reached its write cycle limit or is defective. Replace the memory card.
Fault Code 3: Memory card read error — the CPU cannot read data from the memory card during startup.
Check that the card is fully seated. Clean the card contacts carefully. If the error continues, replace the memory card.
Fault Code 4: Insufficient memory — the user program or data exceeds the available capacity of the memory card.
Reduce the program size or data volume, or replace the card with a higher-capacity memory card compatible with the CPU.
Fault Code 5: Memory card not formatted or corrupted — the card contains invalid or unrecognized data.
Use STEP 7 to reformat or erase the memory card, then re-download the user program. If formatting fails, replace the card.
Fault Code 6: CPU startup fault due to missing memory card — the CPU is configured to require a memory card for load memory but no card is detected.
Insert a valid, programmed memory card into the CPU slot before powering on. Verify the CPU configuration in STEP 7 hardware configuration.

Frequently Asked Questions

What is the storage capacity of the 6ES7952-1AL00-0AA0 memory card?

The 6ES7952-1AL00-0AA0 is a 4 MB Flash EPROM memory card for SIMATIC S7-300 CPUs.

Does this memory card require a battery to retain data?

No. The 6ES7952-1AL00-0AA0 uses Flash EPROM technology, which retains stored programs and data without a backup battery even when power is removed.

Which S7-300 CPUs are compatible with this memory card?

This card is compatible with SIMATIC S7-300 CPUs that feature a memory card slot for external load memory. Compatibility should be verified against the specific CPU's technical documentation in STEP 7.

Can this memory card be reused after erasing the existing program?

Yes, Flash EPROM memory cards can be erased and reprogrammed using SIMATIC STEP 7 software, though Flash memory has a finite number of write/erase cycles.

What programming software is used to write programs to this memory card?

Programs are downloaded to the 6ES7952-1AL00-0AA0 using Siemens SIMATIC STEP 7 software via the connected S7-300 CPU.

Troubleshooting

CPU does not recognize the memory card after insertion

Check that the card is fully and correctly seated in the CPU memory card slot. Inspect the card contacts for contamination or damage.

Remove the card, clean the contacts with a dry lint-free cloth, and re-insert firmly. If the problem persists, test the card in another compatible S7-300 CPU to determine whether the card or the CPU slot is faulty.

Program download to memory card fails in STEP 7

Verify the CPU is in STOP mode before attempting a download. Check the STEP 7 error message for details on whether the issue is a communication error or a memory card write error.

Place the CPU in STOP mode and retry the download. If write errors persist, the card may be at end of life or defective — replace with a new 6ES7952-1AL00-0AA0 or equivalent compatible card.

CPU enters STOP mode immediately after power-on with memory card inserted

The CPU may be detecting a program mismatch, corrupted load memory, or an incompatible program version on the memory card.

Use STEP 7 to read the diagnostics buffer of the CPU for specific fault codes. Erase and re-download the user program to the memory card. Verify the program is compatible with the installed CPU firmware version.

Memory card data lost after power cycle

If data is lost after power removal, the card may not be a genuine Flash EPROM type, or the card may be defective.

Confirm the card part number is 6ES7952-1AL00-0AA0 (Flash EPROM). If confirmed and data loss continues, replace the card as it may have a defective Flash memory cell.

STEP 7 reports insufficient memory when downloading program

The user program, data blocks, or configuration data exceed the 4 MB capacity of the memory card.

Optimize the program by removing unused data blocks or reducing array sizes. Alternatively, replace the memory card with a higher-capacity variant compatible with the target CPU.

Condition	Repair, Used, Refurbished, New in box (sealed)