Technical data

Checking Block Consistency and Time Stamps as a Block Property
15.4 Time Stamps in Shared Data Blocks
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 329
15.4 Time Stamps in Shared Data Blocks
Code Time stamp
The time stamp is updated:
• When an ASCII source file is created for the first time
• When an ASCII source file is compiled
• When changes are made in the declaration view or in the data view of the block
Interface Time stamp
The time stamp is updated:
• When the interface description is changed in the declaration view (changes to data types or
initial values, new parameters)
15.5 Time Stamps in Instance Data Blocks
An instance data block saves the formal parameters and static data for function blocks.
Code Time stamp
The time and date the instance data blocks were created is entered here. The time stamp is
updated when you enter actual values in the data view of the instance data block. The user cannot
make changes to the structure of an instance data block because the structure is derived from the
associated function block (FB) or system function block (SFB).
Interface Time stamp
When an instance data block is created, the interface time stamp of the associated FB or SFB is
entered.
Rules for Opening Without Conflicts
The interface time stamps of the FB/SFB and the associated instance data block must match.
Procedure if a Time stamp Conflict Occurs
If you change the interface of an FB, the interface time stamp of the FB is updated. When you open
an associated instance data block, a time stamp conflict is reported because the time stamps of the
instance data block and the FB no longer match. In the declaration section of the data block the
interface is displayed with the symbols generated by the compiler (pseudo-symbols). The instance
data block can now only be viewed.
To remedy time stamp conflicts of this type, you must create the instance data block for a changed
FB again.