If the CPU ignores the blank card, you may need to first set the CPU to “Program” mode via the DIP switches on older models, though most S7-1500s auto-detect. Part 5: Method 3 – Firmware Update Overwrite (Password Bypass via Upgrade) Siemens frequently releases new firmware for the S7-1500 series. A full firmware update – especially a major version jump (e.g., V2.6 to V2.9) – forces a complete rebuild of the operating system area, which inherently destroys the password. How to Execute: Step 1: Download the Correct Firmware Visit Siemens Industry Online Support. Search for your CPU’s exact order number and download the “Firmware Update for S7-1500 CPU” (file extension .upd ). Do not confuse this with HSP (Hardware Support Package).
You have a blank S7-1500. You can now load a new program. Caveat: This destroys the existing program. Part 4: Method 2 – The Memory Card Trick (Preserving Hardware Config) What if you need to reset the password but keep the I/O configuration and hardware setup? There is a little-known method using a blank SIMATIC Memory Card. The Science Behind the Trick: An S7-1500, when powered on with a blank, bootable memory card inserted, will attempt to load a program from the card. If the card has a valid, unencrypted program, it overwrites the internal load memory. If the card is blank , the CPU will clear its internal memory and revert to factory state, including password removal. Step-by-Step: Step 1: Acquire a Blank Siemens Memory Card You need a card larger than the CPU’s internal memory. For most S7-1500s, a 4GB or 12MB card works. siemens s7-1500 password reset
Click “Reset.” The CPU will execute a secure erase (overwrites memory cells). The LED will flash rapidly. After 30-60 seconds, the CPU will reboot with factory defaults – no password . If the CPU ignores the blank card, you
Format a blank SIMATIC MC card as described in Method 2. Using the SIMATIC Memory Card Utility , write the .upd file to the card as a “Firmware Update Card.” How to Execute: Step 1: Download the Correct
Double-click the discovered CPU to open the “Online & Diagnostics” view. Navigate to Functions → Reset to factory settings .
Power OFF the CPU. Remove the memory card. Power ON again. The CPU is now empty and password-free.