On some models, you can reset the CPU using the physical mode selector switch: Switch off the power and remove any memory cartridges. Hold the switch in the position while powering on.
No password protection; all functions are available. Siemens S7-200 Password Unlock
It resets the baud rate to 9.6 kbit/s and the network address to 2 , returning the CPU to its pristine delivery state. On some models, you can reset the CPU
This is the highest security level. It prevents the program from being uploaded back to a PC, even if you have the correct password. This level is designed to protect industrial intellectual property. Legitimate Methods to Unlock or Reset Access It resets the baud rate to 9
It deletes the user program, data blocks, and configuration information.
This tool is typically found on the original STEP 7-Micro/WIN installation CD. 3. Hardware Factory Reset (MRES)
If you are locked out of an S7-200, Siemens provides official recovery paths. Note that these methods generally involve to regain control of the hardware. 1. The "CLEARPLC" Universal Reset