Mmc Card Format Tool - Siemens
Sourcing clean image files ( .img ) matching your exact card part number can be difficult. Step-by-Step Guide: How to Format an MMC Using a PLC
The safest way to clear a Siemens MMC is through official engineering software. This requires an official Siemens field utility device (Field PG) or a specialized Siemens USB Prommer. Steps for STEP 7 Classic: Insert the MMC into your PG or USB Prommer slot. Open . →right arrow S7 Memory Card →right arrow Open . Select all blocks on the card. Right-click and choose Delete (or use the Delete key). Steps for TIA Portal: Open your project in TIA Portal . Expand the Project Tree on the left. Locate and expand Card Reader/USB memory . Select your specific Siemens card reader slot. Right-click the MMC and select Format . Method 2: The PLC Hardware Slot Method (No Software Needed)
The Siemens MMC card format tool is a software utility designed specifically for formatting MMC cards used in Siemens devices. This tool is developed by Siemens to ensure that MMC cards are properly formatted and functioning correctly. The tool is user-friendly and can be easily downloaded from the Siemens website.
If you do not own an expensive Siemens USB Prommer, you can format and clear the MMC directly inside the PLC CPU using the mode selector switch. When to use this:
Do not attempt to "fix" it using Windows Disk Management. siemens mmc card format tool
When a Siemens MMC becomes corrupted, shows a blinking "MAINT" or "STOP" LED on the PLC, or is accidentally formatted via Windows, you need a specialized to restore its custom partition table. The Golden Rule of Siemens MMCs
Even with the correct tool, you may encounter errors. Here is how to solve them.
Perform an using the CPU switch toggles. Card Unreadable by STEP 7 Card was formatted using Windows File Explorer.
When using recovery tools, you must match your image precisely to your memory capacity. Writing a 512KB image to a 128KB card will permanently corrupt the internal flash controllers. Card Capacity Common Siemens Part Number (MLFB) Primary Use Case 6ES7953-8LF31-0AA0 Small S7-300 Logic Applications 128 KB 6ES7953-8LG31-0AA0 Standard Compact CPUs (e.g., CPU 312C) 512 KB 6ES7953-8LJ31-0AA0 Medium Modular Systems (e.g., CPU 314/315) 2 MB 6ES7953-8LL31-0AA0 Large Codebases & Basic Recipe Storage 4 MB 6ES7953-8LM31-0AA0 Advanced Data Logging / Web Server Hosting 8 MB 6ES7953-8LP31-0AA0 High-End CPUs (e.g., CPU 317 / CPU 319) Troubleshooting Guide Sourcing clean image files (
Siemens Micro Memory Cards (MMCs) are specialized storage media used in SIMATIC S7-300, S7-400, and ET200 PLC systems. Unlike standard commercial SD or MMC cards, Siemens MMCs utilize a proprietary file system format containing critical internal formatting blocks.
Siemens MMC cards (used primarily for S7-300 CPUs) are physically identical to standard MultiMediaCards, but they are logically formatted with a proprietary Siemens structure. Unlike a standard FAT32 or exFAT drive, the Siemens MMC contains a private CID (Card Identification) and CSD (Card Specific Data) register, which stores critical information such as the OEM/application ID and product name. The CPU verifies and cross-references the information stored in these special sectors.
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Report: Siemens SIMATIC Memory Card (MMC) Formatting and Restoration Steps for STEP 7 Classic: Insert the MMC
Here are the safe methods to clear and format your card using standard Siemens software or special hardware. Method 1: Use a Siemens PLC (The Safest Way)
💡 If the tool cannot read the card at all, try a different card reader. Some modern generic USB readers struggle with the proprietary format of Siemens industrial cards.
Use the function to restore a clean, working Siemens .img file onto a corrupted card.
provides a dedicated interface for resetting and formatting cards across multiple devices at once. Select the target CPUs in the device table. Operations > Reset > Format Memory Card Critical Warnings Incompatibility: Standard SD/MMC cards purchased from electronics stores will not work
