Siemens S7 300 313C Memory Card Password Reset

hello Friend

There is one old system with S7 300 CPU which is password protected and I dont know the password.
Now I want to remove the password so what can i do now?...
CPU is not allowing me to upload / download without password.
Is there any way to reset the password of memory card without PG? an by PC - Normal Card Reader

Please guide.

Thanks for your support.

We don't discuss methods to bypass password protection on this forum. You may have a legitimate reason, but there is no way we can be sure. Your best bet is to try to locate the original programmer or the company that initially installed the machine.
You could remove the CPU from the power supply and disconnect the backup battery. That would remove the password while also deleting the program. Then you would be able to reprogram it.

Steve
You must be thinking GE
That won't work with Siemens

Assuming this is one of the newer (last 15 years, ish) style of 300s, with an MMC:

Option A: clear the memory card with a pg or USB prommer, and start from scratch.

Option B: get new Siemens memory card, and start from scratch.

Option C: Call machine builder

I dont have PG and USB Prommer.

Is there any other way, please guide
[email protected]

You can clear the MMC with the CPU RUN-switch:
https://support.industry.siemens.co...fault-reset-or-overall-reset)-?dti=0&lc=en-WW

MMC
It is only possible to reset the MMC if it contains data* that is invalid for the CPU. (* Invalid system data is, for example, data stored for a different type of CPU.) Otherwise the MMC is only initialized by the procedure described.
All the user data is deleted when you reset the SIMATIC Micro Memory Card (MMC). Proceed as follows.

1. The MMC is slotted in the bay of the CPU. The CPU requests an overall reset (slow blinking of the STOP LED).
2. Set the switch to "MRES" and hold it there until the STOP LED lights continuously (approx. 9 seconds).
3. Within the next 3 seconds, you must let the switch go and set it again to "MRES". The STOP LED now blinks during the delete procedure.

If the CPU continues to request an overall reset after the procedure described above, then the MMC is defective.

I tried this but not succes