Dear user,

If changes are made only to the code section of a function block does this allow only the block to be downloaded or does the IDB and the calling block need to be updated and downloaded also? The block in question is a high level block being called from OB1 and contains a number of multi instance FB’s.

For FB in internal layer, your task is more difficult.

Best regards,

hdhosseini

When you say internal layer are you referring to interface changes?

I am unable to stop the process so how do I download by care?

-By internal layer, I mean nested Multi-instance structure and the FB that is used in all other function blocks.See the attached file, any change in interface of FB4 requires an update in all path.

-Any logic change in a running plant may interfere any production line of disturb the safety.To perform online changes,please be sure that they are safe for production line.

I hope it helps,

hdhosseini

What about changes to passing FB/FC parameters?

Changing interface (input,output,static for FB) may require update all FBs to the outer layer like FB1 that is called in OB1 (in previous example).Such a change require IDB re-structure and it is wise to be done while plant is in out-of-service.

For FCs, changing the interface (input,output) may require a consistency problem in your program .As an example ,an added input in an FC wait for an address.Before finalizing your project in STEP 7, be sure it is consistent  and check the whole path manually for double check.

I hope it helps,

hdhosseini