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Weather Station State Machine - Initial State
publish date: 2026/06/13 06:39:45.456666 UTC
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In the weather station state diagram, which state is indicated as the initial state by the unlabelled arrow with a black blob, and what message causes the first transition out of it?
Correct Answer
Initial state: Shutdown; first transition triggered by: restart() message
Explanation
In the weather station state diagram, the unlabelled arrow with a black blob points to the Shutdown state, indicating it is the initial state. The first transition out of Shutdown is triggered by a restart() message, which causes the system to transition to the Running state (normal operation). Both powerSave() and reconfigure() messages in the Shutdown state cause a transition to the Configuring state.
Reference
Software Engineering, Ian Sommerville, 10th edition