Creating Step Sequences - Siemens SIMATIC PCS 7 Configuration Manual

Configuring AS functions

8.4 Creating step sequences

8.4 Creating step sequences
General information about SFCs
The sequential function chart (SFC) is a sequential control system executed in stages which,
depending on certain conditions, advances from one state to the next. A sequential control
system controls functions, such as CFC charts, via mode and state changes, and processes
them selectively.
It is created in the SFC editor. Block icons for SFCs and SFC types are generated automatically
during OS compilation.
Note
Additional information on this is available in the "Process Control System PCS 7
Engineering System" (https://support.industry.siemens.com/cs/ww/en/view/109485969)
manual.
SFC types
In the SFC, there are the "SFC chart" and "SFC type" object types.
The SFC type allows the definition of sequential controls and of an expandable interface. You
can read about the advantages and disadvantages of SFC types/instances in the manual
mentioned above.
Note
The creation of SFC types is described in detail in "Compendium Part C - Technical Functions
with SFC Types".
An SFC type is generally preferred if a step sequencer (SFC) is used several times in the
project. The instances are placed in the CFC chart similar to a function block. The SFC type
is contained in the associated chart folder.
As of PCS 7 V7.0, the SFC type can be centrally edited in the master data library and all
instances in the project can be automatically updated. In addition, ways of accessing the SFC
instances are listed in the chart reference data of the CFC.
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Compendium Part A - Configuration Guidelines (V8.2)
Configuration Manual, 08/2016, A5E38166869-AA