If you work with Siemens PLCs, specifically the S7-300 and S7-400 series, you have likely crossed paths with the dreaded moment when an MMC (Memory Card) decides to misbehave. Maybe the CPU won't go into RUN mode, maybe the "BF" LED is flashing red, or perhaps you are trying to repurpose an old card for a new project.
Whatever the reason, formatting a Siemens MMC card isn't as simple as right-clicking a USB drive on your desktop. It requires specific tools, specific procedures, and a little bit of know-how to avoid bricking the card entirely. siemens mmc card format tool
In this deep dive, we are going to explore everything you need to know about the Siemens MMC Card Format Tool, the procedures for different CPU types, and how to save a corrupted card. The Ultimate Guide to Siemens MMC Card Formatting:
Some engineers use Linux to zero out the first 1MB of the card (dd if=/dev/zero of=/dev/sdb bs=1M count=1). This effectively "bricks" the card in Windows, but sometimes allows the Siemens tool to recover it. Only for experts. specifically the S7-300 and S7-400 series
"Siemens MMC Card Format Tool" – part of Siemens SIMATIC software package, sometimes bundled with STEP 7 or available via S7 Memory Card utilities.