Siemens block interface change and associated DB change

Hey everyone,

I just started out programming Siemens and have a newbie question:

In Siemens Step 7, when I modify the interface of an FB and save, a conflict arises between the FB and the associated instance DB.

When I try to open the DB, the error message is "There are no parameter and local variable names available because there is a time stamp conflict between the interface of the block and the description of the parameter and local variable names."

The only way I know to fix this problem is to delete and recreate the DB. This has to be done at each point in the code where the FB is used (could be a hundred times for motor FBs).

Is there a better way of doing this?

Thanks

James

Try File/Check and update accesses in the LAD/STL/FBD/ editor.

That, or perform a complete "consistency check" on a project.
It is not a big problem as long as you are developing the program offline.
The moment you have to maintain a running program it is not so easy any longer.

Before one gets to the point where the maintenance of the running program start, one should have nailed the declaration part of FBs and FCs.

Use multiple instances then there is only one FB/DB to update.

Multiple instance example:

Thanks everyone,

I have found that Check and Update Accesses works but it only updates the block that is currently selected in the LAD/STL/FBD editor. For cases where FBs are used in multiple blocks, you still have to open each block and use Check and Update Accesses.

The Check Block Consistency seems to fix everything. Problem solved.

Thanks,

James

One of the reasons that i prefer CFC is that all outdated instances are updated in one schmockkk.

Kalle

Or opload and generate a source file for the datablock before modifying the FB interface. The current values are saved. after the FB interface has been changed, compile the DB source and it will put the values back in.