Siemens 6ES7953-8LG20-0AA0 Simatic Memory Card

Siemens 6ES7953-8LG20-0AA0 is a SIMATIC Micro Memory Card (MMC) designed for the S7-300 family, compatible with S7-300 CPUs, C7 modules, and ET 200 devices. It furnishes 128 KB of 3.3 V NFLash non-volatile memory, delivering removable storage for PLC project data and configuration on legacy SIMATIC installations. This order-number-specific card is listed as a spare part under 6ES7953-8LG20-0AA0 and is intended to be used in MMC sockets found on S7-300/C7/ET 200 hardware. The memory card conforms to the MMC format used by Siemens for micro memory cards in these systems, providing a compact, replaceable media option for maintenance, backups, and field servicing of older automation setups where SIMATIC memory media is required. In practice, technicians rely on this 128 KB MMC to maintain compatibility with the S7-300 software tools and to facilitate hardware replacements within manufacturing, packaging, and process control environments that rely on legacy Siemens automation.