Card Format Tool: Siemens Mmc

Doing so overwrites a hidden, proprietary internal structure that makes the card permanently unusable for Siemens CPUs. Siemens SiePortal

Unlike standard MMC cards, — doing so will corrupt the card and make it unusable in the PLC. You must use Siemens-specific software. siemens mmc card format tool

Unlike a standard USB stick which uses generic mass storage drivers, Siemens MMCs contain internal controllers and firmware designed to interact specifically with the S7 CPU. They hold the user program, the hardware configuration, and data blocks. Doing so overwrites a hidden, proprietary internal structure