If you do not need to preserve the online program and simply want to reuse the PLC hardware, you can reset the CPU entirely. Turn the PLC mode switch to STOP .

6ES7314-6CH04-0AB0 SIMATIC S7-300, КОМПАКТНОЕ ЦПУ CPU 314C-2 DP С MPI, 24 DI/16 DO, 4AI, 2AO, 1 PT100, 4 БЫСТРЫХ СЧЁТЧИКА (60 КГЦ) Симэкс SIMATIC S7-300, CPU 314 - 6ES7314-1AF10-0AB0

However, these tools exist in a legal and ethical grey zone. While they can save a plant from a catastrophic shutdown, they also expose a fundamental weakness in legacy industrial protocols: lack of brute-force lockout and weak encryption on the MMC card.

+---------------------------------------------------------------------------------+ | SECURITY WARNING | | Legacy S7-300 components lack the robust cryptographic defense mechanisms found | | in modern TIA Portal architectures. Safeguard physical access to the MMC slot | | to completely mitigate offline extraction vectors. | +---------------------------------------------------------------------------------+ Transitioning to Modern Industrial Security