S7 F System, Creating A Fail-Safe User Program - Siemens SIMATIC S7 F Manual

Getting Started
2.2.3

S7 F System, Creating a Fail-Safe User Program

In the following steps you create a fail-safe CFC user program that interconnects
the fail-safe inputs with the fail-safe outputs.
The Safety Program consists of several charts:
•
At least one chart for user logic program interconnection (F-Blocks)
•
System charts automatically created for diagnostics:
•
Charts for the Safety Critical Diagnostic blocks
•
Charts for the Safety Program Shutdown and Restart Logic
Creating CFC Charts
1. Open SIMATIC Manager, and open the 400 Station in your project.
2. Expand the selections S7 Program to display Source, Blocks and Charts. If the
Charts folder does not exist, create one by right clicking on S7 Program and
select "Insert New Object, Chart Folder".
3. Right click on the Charts folder.
4. Choose a new Chart, and call it "F Blocks".
Creating the Run Sequence
The F function blocks must be inserted in run-time groups. Function Blocks have
not been placed yet. However, you can setup a run-time group to be the default
destination for new F-Blocks.
1. Within your project in SIMATIC Manager, click on the Charts folder.
2. Open the F-Blocks chart by double-clicking on it.
3. Open the Run Sequence either by pressing Control-F11 or selecting Edit>Run
Sequence within the CFC Editor.
4. Select the OB3x that you wish to contain the F-Blocks (OB35 is the most
common) by clicking on the OB3x, in this example, OB35.
5. If the run-time group has not already been added, insert a run-time group by
right clicking on the OB35 and selecting "Insert Run-Time Group...". The
Insert Run-Time Group dialog box will appear.
6. Enter the name of the Run-Time group, in this case call it "F Blocks". Enter a
comment if you desire. Do not change the Scan rate or Phase Offset. Press
OK.
7. Select the run-time group and right-click.
8. Select Predecessor for Installation from the pop-up menu or press F11. By
selecting this option, all newly created F-Blocks will automatically be placed
into this F-run-time group.
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Fail-Safe Systems
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