Technical data

Creating Blocks and Libraries
9.3 Creating Blocks
Programming with STEP 7
232 Manual, 05/2010, A5E02789666-01
In contrast to an offline-online comparison, in an offline-offline comparison, STEP 7also detects the
presence of different variable names. This additional step is not possible for an offline-offline
comparison since only replacement symbols are available online.
Comments for block networks and lines as well as other block attributes (such as S7-PDIAG
information and messages) are excluded from comparisons.
How Block Comparison Works: Data Blocks
In the first step of the process, STEP 7 compares the time stamps for the interfaces of the data
blocks to be compared (as for logic blocks). If these time stamps are identical, STEP 7 assumes
that the data structures are identical.
If the interface time stamps are different, STEP 7 then compares the data structures until the first
difference is found. If the data structures are in the sections are identical, STEP 7 then compares
the initial values and current values. All differences are displayed.
Special feature of offline-offline comparisons:
In contrast to an offline-online comparison, in an offline-offline comparison, STEP 7 also detects
the presence of different variable names. This additional step is not possible for an offline-offline
comparison since only replacement symbols are available online.
Comments and structures for UDTs that are used in a data block are excluded from comparisons.
How Block Comparison Works: Data Types (UDT)
In the first step of the process, STEP 7 compares the time stamps for the interfaces of the data
types to be compared (as for data blocks). If these time stamps are identical, STEP 7 assumes that
the data structures are identical.
If the interface time stamps are different, STEP 7 then compares the data structures until the first
difference is found. If the data structures are in the sections are identical, STEP 7 then compares
the initial values. All differences are displayed.
How Block Comparison Works: Comparison in the Program Editor
1. Open the block to be compared to the loaded version.
2. Select the Options > Compare On-/Offline Partners menu command.
- If the online partner is accessible, then the results of the comparisons will be displayed in
the lower section of the program editor window in the "7:Comparison" tab.
- Tip: If two networks are determined to be "different", then you can open the relevant
network simply by double-clicking in its row.