Siemens SIMATIC S7 System Manual page 165

3. Select what to clear - Program Block, Data Block, System Block, or all blocks, or select
"Reset to factory defaults".
4. Click the Clear button.
Clearing the PLC memory requires the PLC to be in STOP mode and then deletes the
selected blocks or resets the PLC to the factory-set defaults, depending on your selection. A
clear operation does not clear the IP address, station name, or reset the time-of-day clock.
When executed, the "Reset to factory defaults" setting deletes all blocks, resets all user
memory to the initial powerup state, and resets all Special Memory (Page 799) to initial
values.
What to do if you forget the PLC password
If you forget the PLC password (Page 143), you can clear the PLC memory using one of two
methods:
● Use a reset-to-factory-defaults memory card (Page 167) that you have made for this
purpose (standard CPU models).
● Select the "Reset to factory defaults" choice under "Blocks", the "Forgot Password"
choice under "Options", and power cycle the CPU.
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
6.1 Configuring the operation of the PLC system
PLC device configuration
165