Siemens S7-1200 - Recovery from a Lost Password

PLC concepts
4.6 Recovery from a lost password
S7-1200 Programmable controller
136 System Manual, 03/2014, A5E02486680-AG
4.6
Recovery from a lost password
If you have lost the password for a password-protected CPU, use an empty transfer card to
delete the password-protected program. The empty transfer card erases the internal load
memory of the CPU. You can then download a new user program from STEP 7 to the CPU.
For information about the creation and use of an empty transfer card, see the section of
transfer cards (Page 127).
WARNING
Verify that the CPU is not actively running a process before inserting the memory card
If you insert a transfer card in a running CPU, the CPU goes to STOP. Control devices can
fail in an unsafe condition, resulting in unexpected operation of controlled equipment. Such
unexpected operations could result in death or serious injury to personnel, and/or damage
to equipment.
Before inserting a transfer card, always ensure that the CPU is in STOP mode and your
process is in a safe state.
You must remove the transfer card before setting the CPU to RUN mode.