Hierarchical state machine (HSM) means that a state can be drawn within other states.
Typical use of HSM is when overall control must be maintained while two or more states share common interests
or resources. HSM is a general design method to applications that range from user interface design to
real-time control system engineering, where it is most important that the system is able to cope with any
- potentially hazardous - situations. In ReaGeniX HSM large-scale events always override any internal-state
events, and thus, the large-scale design always have full control of the system.