1. There is no legal way to remove unknown password from MMC.
2. If you are the author of the program, then you can simply remove check marks in HW config that related to protection and passwords of the MMC and purchase a new MMC and download the software on it.

S7-200 Manual

Recovering from a Lost Password

If you forget the password, you must clear the memory of the S7-200 and reload your program.

Clearing the memory puts the S7-200 in STOP mode and resets the S7-200 to the factory-set

defaults, except for the network address, baud rate, and the time-of-day clock. To clear your

program in the S7-200:

1. Select the PLC > Clear menu command to display the Clear dialog box.

2. Select all three blocks and confirm your action by clicking OK.

3. If a password had been configured, STEP 7--Micro/WIN displays a password-authorization

dialog box. To clear the password, enter CLEARPLC in the password-authorization dialog

box to continue the Clear All operation. (The CLEARPLC password is not case sensitive.)

The Clear All operation does not remove the program from a memory cartridge. Since the memory

cartridge stores the password along with the program, you must also reprogram the memory

cartridge to remove the lost password.

Warning

Clearing the S7-200 memory causes the outputs to turn off (or in the case of an analog output,

to be frozen at a specific value).

If the S7-200 is connected to equipment when you clear the memory, changes in the state of the

outputs can be transmitted to the equipment. If you had configured the “safe state” for the

outputs to be different from the factory settings, changes in the outputs could cause

unpredictable operation of your equipment, which in turn could cause death or serious injury to

personnel, and/or damage to equipment.

Always follow appropriate safety precautions and ensure that your process is in a safe state

before clearing the S7-200 memory.