How to move DB's

How can I change the name of a DB without having to go through every line of code and changing the inputs and outputs using that DB. EX: If I change DB101 to DB201 then every input that was connected to DB101 is no longer usable.

Set the program for symbolic priority, then re-gen the code after the change.

How do you set the symbolic priority and then re-gen?

I don't have access to Step 7, so cannot be sure on the buttons.

For Symbolic programming, I believe you right click on the folder that contains the blocks and select properties. The last tab shows the programming priority selections, it will have 4 squares, each with a click point in, the default is the top left (address priority), I always change to the bottom right (symbolic priority).

Once you have done that, it means that when you regen, the addresses will follow the symbol.

So now you could go to the symbol table and change the DB address, but then you would have to re-gen (or go to every instance of the DB usage).

I'm not sure what the official name of the regen function is, I do know you get to it from the the top drop down menu's. Its a function that shows the code in its structure and highlights any errors in the blocks, within that there's the regen option, do the regen and the code will be updated.

Save and download.


Of course you woluld have to be carefull downloading, it would be better with the process stopped, as the code will download errors may occur in the PLC if running.


Hopefully someone else who knows what I am talking about here will read the thread and correct anything. Its useful to know this especially, if like me when coding in S7, you use a lot of UDT's.

I have never used the symbolic priority option so cannot comment, however, here is one method.

My example only contains OB1 that references DB101 but the principal remains the same.

From the block editor select File>Generate Source

You have to enter an Object name for the source code - I've used the name "Code". Note that the source will be created in the sources folder.

Click on OK and your blocks will appear on the Left hand side - select the blocks that reference the DB you wish change (or just select all OB, FB and FC's) and then click on the right arrow:

Then click on OK

As OB1 is open in my example, a warning will appear - click on Yes to continue

Close down the block editor and navigate to the source folder in Simatic Manager

Double click on the Code object in the right hand pane and the block editor will open showing the source code:

Use Edit to find/Replace DB101 with DB201 (Replace all)

Click on File>Compile to compile the source.

Close down the editor and (discard the changes).
The blocks folder will now contain the re-compiled blocks with DB101 replaced by DB201.

Downside - if the blocks were created by the ladder editor they will now show as being created in STL. They will still be displayable in ladder.