SIMATIC S7 Micro Memory Card S7 300, C7, or ET 200 series CPU, 6ES7953-8LL31-0AA0

? Overview

• Product Type: SIMATIC S7 Micro Memory Card for S7‑300, C7, or ET‑200 series CPUs. It stores user programs and data such as blocks, configuration, and recipes

? Technical Specifications

• Memory Size: 2 MB Flash-EPROM
• Voltage: Operates at 3.3 V N‑Flash
• Durability:
• Minimum 100,000 write/erase cycles
• Data retention: at least 10 years
• Size & Weight:
• Dimensions: 24 mm × 32 mm × 1.4 mm
• Weight: approx. 2 g

? Lifecycle & Availability

• Phase‑out status: Officially in phase‑out as of October 1, 2023; still available until stock depletes
• Typical lead time: ~10 working days from factory

✅ Use Cases & Compatibility

• Purpose: Retains CPU configuration/programs when power is off.
• Compatible with:
• CPUs: S7‑300 series, C7, ET‑200 modules.
• Replaces other MMC cards in Siemens S7 systems, ensuring proper storage

⚠️ Recommendations

1. Backup Data Regularly: Though rated for long-term retention, critical system data should be backed up or duplicated.
2. Keep Spares: The phase-out means replacements may be harder to find—keeping an extra is wise.
3. Verify Compatibility: For newer S7-300 or ET systems, ensure your firmware supports this older MMC; newer CPUs may use 8 MB versions (6ES7 953‑8LP31‑0AA0, etc.).

? Summary