Technical data

Checking Block Consistency and Time Stamps as a Block Property
15.2 Time Stamps as a Block Property and Time Stamp Conflicts
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 327
15.2 Time Stamps as a Block Property and Time Stamp Conflicts
Blocks contain a code time stamp and an interface time stamp. These time stamps are displayed in
the dialog box for the block properties. You can monitor the consistency of STEP 7 programs
using time stamps.
STEP 7 displays a time stamp conflict if it detects a violation of the rules when comparing time
stamps. The following violations may occur:
• A called block is more up-to-date than the calling block (CALL)
• A referenced block is more up-to-date than the block which is using it
• Examples of the second type of violation:
• A UDT is more up-to-date than the block that is using it; that is, a DB or another UDT, or an
FC, an FB, or an OB that is using the UDT in the variable declaration table.
• An FB is more up-to-date than its corresponding instance DB.
• An FB2 is defined as a multiple instance in FB1 and FB2 is more up-to-date than FB1.
Note
Even if the relationship between the interface time stamps is correct, inconsistencies may occur:
• The definition of the interface for the referenced block does not match the definition in the location at which it
is used.
These inconsistencies are known as interface conflicts. They can occur, for example, when blocks are
copied from different programs or when an ASCII source file is compiled and not all of the blocks in a
program are generated.