Hierarchy of SFC programs

Each SFC"Sequential function chart" It can be used to program processes that can be split into steps. The main components of SFC are: - Steps with associated actions - Transitions with associated logic conditions - Directed links between steps and transitions program can have one or more "child programs". Child programs are written in SFC and are started (launched) or stopped (killed) in the actions of the father program. A child program can also have children. The number of hierarchy levels must not exceed 19.

When a child program is stopped, its children are also implicitly stopped.

When a child program is started, it must explicitly in its actions start its children.

A child program is controlled (started or stopped) from the action blocks of its parent program. Designing a child program is a simple way to program an action block in SFC language.

Using child programs is very useful for designing a complex process and separate operations due to different aspects of the process. For instance, it is common to manage the execution modes in a parent program and to handle details of the process operations in child programs.