Step7: Changing DB names

I am well into a project where I have created a lot of DB's as shared blocks and instance blocks. It will eventually control six identical manifolds so there will be a lot of FB's with 6 instance DB's.

Now that I see the program layout more clearly (finally), I would like to rearrange some of my DB naming so it looks better organized in the Blocks screen.

Can this be done without breaking everything?

Should just be able to in the symbol table

You have look at options, there you can choose between absolute and symbolic address priority.

Now if you for instance have used DBI like:
Call "Manifold", "ManifoldData1"

and those are really FB1 and DB1

Then if you change symbol to point to DB2 and have absolute address priority, the call will end up looking like:
Call "Manifold", DB1

If you have symbolic, it be:
Call "Manifold", "ManifoldData1"
and ManifoldData1 will point to DB2.

So it basically needs to be looked how your program done and what you want to change. So do you want to change DBnums or DB symbols?

MartyW said:

It will eventually control six identical manifolds so there will be a lot of FB's with 6 instance DB's.

Click to expand...

It may interest you to know that you can reduce the number of instance DBs by combining all your calls in one block.

The attached picture shows FB6 open in the editor. In the STAT section of the header you can see that two other FBs have been declared: fbDriveCycle as fbDriveCycle and fbKpos as fbKnivePosioning. Also shown is he all to fbKpos, note that it des not require its own instance Db as all of the instance data is declared in the header of FB6 and is therefore included within the instance db for FB6.

You could declare all your manifold FBs in the header of one other FB and have only one instance DB.

Nick