examples

Charging Station

input / state	Ready	Occupied	Charging	Unavailable
Plugged In	Occupied	-	-	-
Plugged Out	-	Ready	Ready	-
RFID Tag	- / Occupied	- / Charging	- / Occupied	-
Remote Start	Occupied	- / Charging	-	-
Remote Stop	-	-	Occupied	-
Timed Out	-	- / Ready	-	-
Hardware Errors	Unavailable	Unavailable	Unavailable	-
Hardware Recovery	-	-	-	Ready / Occupied

• -/Occupied or -/Charging indicates to stay in the current state or transition to the next state
  • For example, if RFID tagged in the Occupied state:
    • If authorization is successful while plugged in, transition to Charging state
    • Otherwise, stay in current state
• States
  • Ready
  • Occupied
    • Charging can only happen in Occupied, so it would be nice to have a more independent term than Occupied. Need to include preparing and finishing states
  • Charging
    • Suspended and finished charging are also included in this state
  • Unavailable
    • Emergency button also included in this state.

Diagram

State Transition Table

Current state	Event	Action	Prev. state	Next state
Ready	Plug in	-	-	Occupied
Ready	Remote start	TimerStart	-	Occupied
Ready	RFID tag	TimerStart	-	Occupied
Occupied	Plug in	RelayOn	-	Charging
Occupied	Remote start	RelayOn	-	Charging
Occupied	RFID tag	RelayOn	-	Charging
Occupied	Timed out	-	Ready	Ready
Occupied	Fail/Not accepted	-	Ready	Ready
Occupied	Plug out	-	-	Ready
Charging	Remote stop	RelayOff	-	Occupied
Charging	RFID tag	RelayOff	-	Occupied
Charging	SuspendedEV	RelayOff	-	Charging
Charging	Resume suspended	RelayOn	Charging	Charging
Charging	Plug out	RelayOff	-	Ready
Ready	Hardware errors	-	-	Unavailable
Occupied	Hardware errors	-	-	Unavailable
Charging	Hardware errors	-	-	Unavailable
Unavailable	Hardware recovery	-	Ready	Ready
Unavailable	Hardware recovery	-	Occupied	Occupied
Unavailable	Hardware recovery	-	Charging	Occupied