Example: Door

Here is an informal sketch of a state diagram showing the effect of locking a door (it cannot be opened in the locked state):

state diagram of Door

Here is the definition of the same state diagram using the notation of the LTSA tool:

UNLOCKED = (open -> OPEN | lock -> LOCKED),
OPEN = (close -> UNLOCKED),
LOCKED = (unlock -> UNLOCKED).

How would you model this system using the FSM formalism (with input and output messages) ?

Created: December 17, 2008