Siemens 6ES7 952-1AL00-0AA0 Service-Ready Spare Part

Siemens 6ES7 952-1AL00-0AA0 Service-Ready Spare Part for Industrial Maintenance

The Siemens 6ES7 952-1AL00-0AA0 is an original Flash Memory Card designed for use with the SIMATIC S7-300 and SIMATIC S7-400 programmable logic controller platforms. As a critical data storage component within the CPU module, this memory card retains the user program, data blocks, and configuration parameters even during power-off cycles, making it indispensable for rapid system recovery and unplanned downtime mitigation in industrial automation environments.

For maintenance engineers managing aging SIMATIC S7-300 or S7-400 control systems, sourcing a verified, service-ready replacement for the 6ES7 952-1AL00-0AA0 is a top priority. Program loss due to a failed or corrupted memory card can halt an entire production line. Stocking this spare part as part of a proactive maintenance inventory strategy ensures that any CPU replacement or memory card failure can be resolved within minutes rather than days.

At NINERMAS, every unit of the 6ES7 952-1AL00-0AA0 is sourced from verified supply channels, inspected prior to dispatch, and covered by a 12-month warranty. We support long-term procurement programs for MRO teams and system integrators requiring consistent, reliable access to legacy Siemens SIMATIC spare parts.

Spare Maintenance Table

Maintenance Planning for Continuous Operation

When replacing the 6ES7 952-1AL00-0AA0 memory card in a SIMATIC S7-300 or S7-400 system, a thorough inspection of the surrounding control cabinet components is strongly recommended to prevent repeat failures and ensure full system restoration.

Begin with the CPU module itself — units such as the 6ES7 315-2EH14-0AB0 (CPU 315-2 PN/DP) or 6ES7 317-2EK14-0AB0 (CPU 317-2 PN/DP) should be checked for firmware version compatibility with the replacement memory card. A mismatched firmware version can prevent the CPU from reading the card correctly after insertion.

Next, inspect the power supply module. The 6ES7 307-1EA01-0AA0 (PS 307, 5A) or 6ES7 307-1KA02-0AA0 (PS 307, 10A) should be verified for stable 24 VDC output. Voltage fluctuations during a memory card write cycle are a known cause of data corruption and card failure. A worn or undersized power supply is frequently overlooked during fault diagnosis.

The backplane bus connector and rack assembly — such as the 6ES7 390-1AE80-0AA0 (Rail 480mm) — should be inspected for oxidation or mechanical damage, particularly in high-vibration or high-humidity environments. Poor rack contact can cause intermittent CPU faults that are misdiagnosed as memory card errors.

For systems using PROFIBUS DP communication, verify the integrity of the 6ES7 972-0BB52-0XA0 PROFIBUS connector and associated DP cables. A degraded communication bus can cause the CPU to enter STOP mode, which may be incorrectly attributed to a memory card fault.

If the control cabinet includes digital or analog I/O modules such as the 6ES7 321-1BL00-0AA0 (DI 32×DC24V) or 6ES7 331-7KF02-0AB0 (AI 8×12Bit), confirm that all module addresses and parameter assignments are correctly stored in the replacement memory card before returning the system to service. Missing I/O configuration is a common post-replacement issue.

Additionally, check signal isolators, terminal blocks (e.g., Phoenix Contact or Weidmüller series), and 24 VDC fuse protection on field wiring circuits. These passive components are often neglected during emergency replacements but can be the root cause of recurring CPU faults.

For facilities running WinCC or SIMATIC HMI panels (such as the TP700 Comfort or MP377), confirm that the HMI project is synchronized with the updated CPU program after the memory card swap to avoid operator screen errors or tag mismatch alarms.

Site Replacement Workflow

Step 1 — Pre-replacement backup: Using STEP 7 (v5.x) or TIA Portal, upload and archive the existing CPU program, data blocks, and hardware configuration to an engineering workstation. Confirm the backup is complete before proceeding.

Step 2 — Power-down and card extraction: Switch the CPU to STOP mode. For non-hot-swap CPUs, power down the rack before removing the existing 6ES7 952-1AL00-0AA0. Handle the card by its edges to avoid ESD damage.

Step 3 — Inspect and clean the card slot: Check the CPU card slot for debris, corrosion, or bent contacts. Clean with compressed air if necessary. A damaged slot will cause read errors even with a new card.

Step 4 — Insert replacement card: Insert the new 6ES7 952-1AL00-0AA0 firmly until it clicks into place. Power up the rack and observe the CPU LEDs — the STOP LED should illuminate, indicating the CPU is ready to receive the program.

Step 5 — Program download: Download the archived program from the engineering workstation to the CPU. Verify all data blocks and hardware configuration are transferred correctly. Perform a CPU memory reset (MRES) if required before download.

Step 6 — System validation: Switch the CPU to RUN mode. Monitor the diagnostic buffer for any fault entries. Confirm all I/O modules, communication links, and HMI connections are operating normally before releasing the system to production.

This workflow minimizes downtime and ensures a clean, validated restoration of the control system — reducing the risk of secondary faults caused by incomplete program transfers or configuration mismatches.

Spare Parts Support FAQ

Q1: Is the 6ES7 952-1AL00-0AA0 compatible with all SIMATIC S7-300 CPUs?
The 6ES7 952-1AL00-0AA0 is compatible with the majority of SIMATIC S7-300 CPU modules that feature a memory card slot, including CPU 312, 314, 315, 317, and 319 variants. Compatibility with specific S7-400 CPUs should be verified against the Siemens hardware catalog or the CPU’s technical data sheet. NINERMAS can assist with compatibility verification prior to order confirmation.

Q2: What does the 12-month warranty cover?
The 12-month warranty covers manufacturing defects, functional failures under normal operating conditions, and pre-shipment test failures identified after delivery. Each unit undergoes functional verification and visual inspection before dispatch. Warranty claims are processed directly through NINERMAS with a target response time of 48 hours.

Q3: Can NINERMAS support long-term or blanket purchase orders for this part?
Yes. NINERMAS offers long-term supply agreements and blanket PO arrangements for MRO teams and system integrators requiring consistent access to the 6ES7 952-1AL00-0AA0 and related SIMATIC S7-300/S7-400 spare parts. Stock reservation and lead-time commitments are available upon request. Contact our sales team to discuss volume pricing and delivery schedules.

Q4: How should the 6ES7 952-1AL00-0AA0 be stored as a spare part?
Store the memory card in its original anti-static packaging in a dry, temperature-controlled environment (recommended: 15°C to 25°C, relative humidity below 60%). Avoid exposure to direct sunlight, magnetic fields, or mechanical shock. Inspect the card annually as part of your spare parts inventory audit to confirm it remains in serviceable condition.