Siemens S7-300 Replacement procedure

Hi all,

Good day. I have experienced in Allen bradley but i'm very new to the siemens plC & sorru for asked basics. in my plant one of the Siemes S7 300 pLC cpu decided to replace, and it has the hardware number of (6ESS7 313 - 5BF03-0AB0) and currently it has the mmc inserted on the CPU. After went to online with PLC when i selected retrieve from memory card it shows empy on that field. The replaceement spare CPU we have same model hardware number. But i don't know from where exactly i will check my current PLC firmware version. But the spare we have the firmware version of 2.11. Could you please tell us what are all the basic and proper procedures has to follow.

wether if i remove the old MMC card from the existing CPU and if i inserted on the sapre new CPU wehter it would be enough to resume the machine?

IS there any firmware version has to be update to operate this CPU, such like allen bradley necessarily need to update firmware to the needed version?

How can able to know that the Current inserted mmc has the Hardware configuration & Blocks.

Siemens is usually quite nice allowing different firmware revisions to start up, it'll display an error pointing to the discrepancy though.

These CPUs store their programs on the memory card. If the machine is running, the program is on the card.

Yes, if you move the MMC to the new unit before applying power it should work fine, as cardosocea says.


If you are using Simatic Manager:

If you have the current PLC project, navigate to the Program Blocks folder and go online. In the Online window you will see which blocks are present on the memory card.

To find the firmware version, highlight any block and press CTRL + D to open the module properties. I believe the firmware version is given here. If it is not, view Accessible Nodes. When the CPU is shown, select View > Details and the window will have a firmware version column.


If you are using Portal, use the Online Access folder to browse your CPU and see the blocks on the memory card. Select Online & diagnostics to view the module properties. Firmware version is listed here.