How to solve problem with MMC

[Guest MAL]

Hi all I need your helps to solve the problem with my Simatic MMC (micro memory card). I am utilizing a Simatic CPU 314C-2DP (with firmware V1.0). According to the informations I read in Siemens's website, this type of CPU must be used with a micro memory card (MMC) in order to be able to save user programme and data. So I bought a MMC of type 6ES7953-8LG11-0AA0. I have formatted this MMC as it is instructed in the Manual of CPU31xC. I plugged this MMC into CPU314C-2DP and tried to connect this CPU with a PC installed Step V5.3 but PC have always informed that it couldn't communicate with PLC. But when I removed the MMC out of of PLC's slot and reset the PLC, it could easily communicate with PC and in the dianostig buffer I saw the message " Illegal memory submodule:replace submodule and reset memory". So, is this MMC not proper for the CPU314C-2DP? In my opinion I don't think this MMC is not permitted for CPU314C because Siemens didn't say that in its manual and catalog. But I haven't found yet any solution for this kind of problem. Please instruct me by your experiences in using CPU314C and MMC. Thanks

[DesertDog]

I have used several of these without any problems. I don't know how you formated it or what the recomended procedure is but mine have always come pre-formatted. I do know that although a standard SD reader will see these cards they will claim they are not formated because Siemens uses a non standard format. Formating one of these as a standard SD will prevent the CPU from being able to read it.

[Guest Guest]

Hello DesertDog For the first time when I plugged MMC into CPU314C's slot the CPU314C couldn't communicate with PC. After that I removed MMC out of my PLC and recognised that the PLC could connect with PC quite normally. So at that time I supposed MMC possibly had been delivered unformatted and I decided to format MMC by following the procedure of Siemens. Here is the format procedure of MMC described in the manual of CPU314C: 1. Your CPU requests an overall reset (slow flashing of the STOP LED). 2. Put the switch into the MRES position and hold it there until the STOP LED lights permanently (approx. 9 seconds). 3. You must then release the switch within the next 3 seconds and then put it back into the MRES position. The STOP-LED now flashes during formatting I have completely done as the procedure instructed but the result as you know are still unchanged. Do you have any idea or suggestion ?

[Guest Guest]

MAL, There is nothing that you should have to do to the MMC in order to get it working. The MMCs are preformatted to the OS of the PLC. If you somehow reformatted the MMC then it is FUBAR. There is no way for anyone but the factory to reformat the MMC to the Siemens OS. If you used a standard SD card reader and had your computer reformat it then it is now reformatted to a regular SD card for your windows OS. What you have is a VERY expensive 8M SD. All you should have to do is stick the MMC in and download your program. Now if there is some compile issues with your program due to memory addresses or so then yes you would have problems downloading to the MMC. You purchased a 128K MMC and all that is truely required at a minimum is the 48K MMC so you are safe there.

[RMA]

There is a known problem with the current series of MMCs - those with 8Lx11 in the part number. The problem is solved with Step7 V5.3. If you have Step7 V5.2 there is a Hotfix available on the Siemens website here.

[Guest MAL]

Hello RMA I am using Step 7 Ver5.3 so I think we can extinguish the reason of software's errors as mentioned about Step7 ver5.2 in Siemens website. I think I should describe the problem again because some men has been misunderstanding the phenomenon of problem. First of all I would like to emphasize that because the PLC can't not recognise the MMC therefore PLC can't communicate with PC and consequently I couldn't download any program to PLC( to take this download action we need first to establish the connection between PLC and PC). And the second is I have not got a SD card reader . I only formatted MMC by sticking it into PLC's memory card slot and following exactly the procedure Siemens has suggested. And now the problem still exist

[RMA]

The current generation of Siemens MMCs is very unreliable. If you haven't got an external Prommer, then your only choice is to send it back to Siemens for "repair". Yes, they do actually repair them, because it's a formatting problem. As far as I'm aware, they don't charge for this service, at least they don't in Germany.

[johnnyD]

Here is a link for some MMC tools: http://personal.telefonica.terra.es/web/suwe/ There are two programs on this site: one for reading a Siemens MMC with an ordinairy card reader, and one for writing. Reading will generate an image file, which can be read by the writing tool. All you need now is someone who can make you an image of the same MMC card using the same CPU. Then you can write this image file back to your own MMC card. Did you never use the card in an other type of CPU? Because if the hardware configuration stored on the card doesn't match the CPU type you are using it on, you also get this problem.

[Guest bernd]

some images you can find here: http://kingleech.ki.funpic.de/wbblite/index.php (under database-simatic-tools-mmctools) this image files where created with the mmc-tools software. good luck! cu

[hesammhd]

Hi

How can i erase the S7-300 128KB MMC memorry

[collinsd70]

On 5/10/2019 at 9:29 AM, hesammhd said:

Hi

How can i erase the S7-300 128KB MMC memorry

You can use the S7Writer above in conjunction with a blank image file.

The alternative is to put in a CPU and power on- select "run" then hold switch in "res" position- once stop light stops blinking quickly release lever and push back to stop.

Once stop light stops flashing- memory card has been cleared.

 

 

Regards

Daniel