The door - open button in Figure 5.2 is of momentary - pressure type. Hence, it is enough to press the button momentarily to open the door.

However, when there is a fi re in the building and the elevator is switched to in - car fireman service , the doors are not operated automatically anymore, but a fire fighter operates the doors directly with door open/close buttons; no safety sensors or timeouts are in use. Besides, the door - open button is then of constant - pressure type. That is, the fire fighter must press the button constantly until the door is fully open, otherwise the door will reclose swiftly (what is the motivation behind this functionality?).

Redraw the finite state machine to fulfill the requirements of in - car fireman service.

Figure 5.2

Transcribed Image Text:

Else Open Else Fault C CC, CB DO OB, SE, PC OB, SE, PC Closing T2 T1 Else Else CB Opening Nudging DC OC, OB DC 73 T3 Closed Fault O Else