If you have a Siemens PG (Programming Device) or a compatible external Prommer (e.g., USB Prommer 6ES7792-0AA00-0XA0), you can format the card directly in the software. Insert the MMC into the PG/Prommer.
If the PLC fails to complete the MRES process, the card might be permanently damaged.
The PLC will reject the card with a flashing or "MAINT" LED. The PLC will continuously request a memory reset (MRES).
When using MMC cards in industrial applications, it's not uncommon for them to become corrupted or require formatting. This can happen due to various reasons, such as power failures, software crashes, or physical damage. When an MMC card becomes corrupted, it may not be recognized by the device it's inserted into, or it may not function correctly. In such cases, formatting the card is often the best solution. However, formatting an MMC card requires specialized software, which is where the Siemens MMC card format tool comes in.
Standard Windows format tools (FAT32/NTFS) cannot properly format these cards. Doing so will corrupt the MMC, making it unusable in a Siemens PLC. Methods for "Formatting" Siemens MMC Cards
Insert the corrupted MMC into your PC's standard card reader. If Windows prompts you to format the disk, click . Run the S7ImgWR utility as an Administrator. Select the drive letter corresponding to your card reader.
You will see a dialog: "MMC formatting completed successfully."
: Choose the drive letter corresponding to your card reader within S7ImgRD.
The Siemens MMC card format tool is not a simple, official software download. It is a set of practices ranging from using the CPU's MRES switch for a basic reset, to using specialized hardware like the USB Prommer with official Siemens software, and finally, to employing powerful community tools like S7imgWR for disaster recovery.