PLC Program Storage Solution – SIEMENS 6ES7953-8LG31-0AA0 | SIMATIC S7-300
Where This Product Is Used
The SIEMENS 6ES7953-8LG31-0AA0 S7 Micro Memory Card (128KB) is a plug-in flash-based memory module designed exclusively for the SIMATIC S7-300 programmable logic controller family. It is deployed across a wide range of industrial automation environments where reliable, non-volatile program storage is critical:
- Automotive assembly lines – stores ladder logic and function block programs for robotic welding, stamping, and paint-shop conveyors
- Food & beverage processing – retains PLC programs through power cycles in washdown and temperature-variable environments
- Water & wastewater treatment plants – provides persistent program backup for pump control, dosing, and SCADA-linked S7-300 CPUs
- Pharmaceutical manufacturing – supports validated program versions in GMP-regulated production cells
- Building automation & HVAC – used in S7-300 controllers managing chillers, AHUs, and BMS integration nodes
- Machine tool & CNC integration – stores motion-control programs for milling, turning, and grinding machine PLCs
- Oil & gas field panels – deployed in remote RTU cabinets where program integrity must survive power interruptions
Technical Specifications
| Part Number | 6ES7953-8LG31-0AA0 |
| Description | S7 Micro Memory Card, 128 KB |
| Compatible Systems | SIMATIC S7-300 CPUs (all variants supporting MMC) |
| Memory Type | Flash EEPROM (non-volatile, battery-free) |
| Capacity | 128 KB |
| Form Factor | Micro Memory Card (MMC), plug-in module |
| Data Retention | 10 years (typical, without power) |
| Write Cycles | 100,000 (typical) |
| Operating Temperature | 0 °C to +60 °C |
| Storage Temperature | –20 °C to +85 °C |
| Weight | approx. 40 g |
| SIEMENS Product Family | SIMATIC S7-300 Accessories |
Why Engineers Specify This Model
- Battery-free program retention – Flash EEPROM eliminates the risk of program loss due to battery failure, a critical advantage over older RAM-based backup solutions.
- Plug-and-play CPU replacement – Insert the MMC into a replacement CPU and the program loads automatically on power-up, minimizing downtime during hardware swaps.
- Exact OEM specification – The 6ES7953-8LG31-0AA0 is the factory-specified card for S7-300 CPUs requiring 128KB load memory; no compatibility guesswork required.
- Firmware & data block storage – Beyond user programs, the card stores data blocks and CPU firmware updates, making it the single source of truth for the controller’s configuration.
- Proven field reliability – Widely deployed in millions of S7-300 installations globally since the platform’s introduction; a known-good, low-risk component choice.
Complete System Bill of Materials
When integrating this memory card into an S7-300 control system, the following companion components are typically specified:
- SIMATIC S7-300 CPU (e.g., CPU 314, CPU 315-2 DP, CPU 317-2 PN/DP)
- SIMATIC S7-300 Power Supply Module (PS 307, 2A / 5A / 10A)
- SIMATIC S7-300 Digital I/O Modules (SM 321 / SM 322)
- SIMATIC S7-300 Analog I/O Modules (SM 331 / SM 332)
- SIMATIC S7-300 DIN Rail & Bus Connectors
- STEP 7 / TIA Portal programming software (for program download to MMC)
- PC Adapter USB / MPI/PROFIBUS programming cable
Contact support@konmask.com for bundle pricing on complete S7-300 system builds.
Compliance & Industry Standards
- CE Marking – Compliant with EU Low Voltage and EMC Directives
- UL Listed – Recognized under applicable UL standards for industrial control equipment
- IEC 61131-2 – Programmable controllers hardware requirements
- RoHS Compliant – Restriction of Hazardous Substances (EU Directive 2011/65/EU)
- ATEX / IECEx – Consult factory for hazardous-area deployment guidance
- ISO 9001 – Manufactured under SIEMENS’ certified quality management system
Quality Assurance & Sourcing
Konmask.com specializes in the procurement of genuine and verified industrial automation components. Our sourcing process for the 6ES7953-8LG31-0AA0 includes:
- Direct procurement from authorized SIEMENS distribution channels and verified surplus inventories
- Visual and functional inspection prior to dispatch
- Original manufacturer packaging preserved where available
- Traceability documentation available upon request for regulated industries
- Secure anti-static packaging for all memory card shipments
How to Source This Part
- Add to cart – Place your order directly on this page for in-stock units.
- Request a quote – For volume orders (>5 units) or project BOM sourcing, email support@konmask.com for preferential pricing.
- Urgent requirement – Call or WhatsApp +0086 19859288691 for same-day response on critical plant-down situations.
- Cross-reference check – If you are unsure whether this card matches your CPU variant, share your CPU part number and we will confirm compatibility before shipment.
Application-Specific FAQ
Q: Can I use the 6ES7953-8LG31-0AA0 with an S7-400 CPU?
A: No. This Micro Memory Card is designed exclusively for the S7-300 family. S7-400 CPUs use a different memory card form factor (6ES7952-xxxx series).
Q: Do I need to format the card before first use?
A: New cards are pre-formatted. If reusing a card, formatting via STEP 7 or TIA Portal is recommended to clear previous program data.
Q: Will the program survive a complete power loss?
A: Yes. Flash EEPROM retains data indefinitely without power — no battery backup is required.
Q: What is the maximum program size this card supports?
A: 128KB of load memory. Usable capacity for user programs depends on the CPU’s work memory; consult your CPU datasheet for the effective program size limit.
Q: Can this card store data blocks (DBs) as well as OBs/FBs/FCs?
A: Yes. All S7-300 program objects — OBs, FBs, FCs, DBs, and SDBs — are stored on the MMC as load memory.
Q: Is this card compatible with TIA Portal as well as STEP 7 Classic?
A: Yes, provided the target CPU supports TIA Portal. The physical card is the same; compatibility is determined by the CPU firmware version.
© 2026 Konmask.com. All rights reserved.
Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
