Technical data

Creating Blocks and Libraries
9.2 Selecting the Programming Language
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 223
9.2.6 S7 HiGraph Programming Language (State Graph)
The graphic programming language S7 HiGraph is available as an optional package. It allows you
to program a number of the blocks in your program as status graphs. Here you split your system
into dedicated functional units which can acquire different states and you define the transition
conditions between states. You describe the actions assigned to the states and the conditions for
the transitions between the states in a zoom-type language similar to Statement List.
You create a graph for each functional unit that describes the response of this functional unit. The
plant graphs are gathered in graph groups. The graphs can communicate to synchronize functional
units.
The well arranged view of the status transitions of a functional unit allows systematic programming
and simplifies debugging. The difference between S7-GRAPH and S7-HiGraph is, that the latter
acquires only one state (in S7-GRAPH: "step") at any one time. The figure below shows how to
create graphs for functional units (example).