S7 300

[Sarang_hecp]

Hello!
How to download new project in password protected MMC in S7-300 CPU without having spare MMC, field PG and another CPU? Please help...

 

[IJK]

do u know the password of the current mmc if yes u can clear and reset the mmc and the download the new project

if u dont know the password then u have to crack the password first

send me u r mail id so that i can tell u the exact meathod of cracking mmc password

 

[JesperMP]

If you have a CPU of a different type, then you should be able to clear the MMC completely in that CPU.

From Siemens FAQ:

MMC
It is only possible to reset the MMC if it contains data* that is invalid for the CPU. Otherwise the MMC is only initialized by the procedure described.
* Invalid system data is, for example, data stored for a different type of CPU.

How to do it:

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.

 

[sebastien2]

Hi Sarang, here is an aditionnal tip : if you have a F CPU, and the safety functionnality is activated for that CPU, you can still reload the complete program onto the MMC (but it has to be the one that was onto that MMC before, or it has to be a new MMC).
In Simatic Manager (Step7), do ONE left clic on the bloc folder. Then go to Step7 menu 'System cible' and select 'load user program onto the MMC' (sorry but my Step7 is in french version, you must find the appropriate translation ;-)
Just make sure to go to the top menu of Step7 (it's not the same than to do a rigth click on bloc folder, and load the program !)
Tell us if this works

Aditionnal infos : once you have put a 'safe' program onto an MMC, the only way to completely remove it from the MMC is to have a Simatic PG field with Siemens MMC slot, or to have the Siemens MMC programmer, or to use a tool from this post : http://www.plctalk.net/qanda/showthread.php?t=21758&highlight=siemens+MMC
with this link : http://personal.telefonica.terra.es/web/suwe/

 

[Sarang_hecp]

Hi Sarang, here is an aditionnal tip : if you have a F CPU, and the safety functionnality is activated for that CPU, you can still reload the complete program onto the MMC (but it has to be the one that was onto that MMC before, or it has to be a new MMC).
In Simatic Manager (Step7), do ONE left clic on the bloc folder. Then go to Step7 menu 'System cible' and select 'load user program onto the MMC' (sorry but my Step7 is in french version, you must find the appropriate translation ;-)
Just make sure to go to the top menu of Step7 (it's not the same than to do a rigth click on bloc folder, and load the program !)
Tell us if this works

Aditionnal infos : once you have put a 'safe' program onto an MMC, the only way to completely remove it from the MMC is to have a Simatic PG field with Siemens MMC slot, or to have the Siemens MMC programmer, or to use a tool from this post : http://www.plctalk.net/qanda/showthread.php?t=21758&highlight=siemens+MMC
with this link : http://personal.telefonica.terra.es/web/suwe/

Thanks for kind reply. Bust sorry, now i can not try all this. Because this project is finished now. We bought new MMC and solved this problem. We were not having sufficient time to buy new MMC, but we had no choice.
Anyways, thanks a lot.