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Author Topic: lifts, does pressing the buttons do anything?  (Read 2818 times)

paul.fr

  • Guest
lifts, does pressing the buttons do anything?
« on: 23/11/2007 08:04:56 »
See those lifts that have two buttons, up and down. Does it actually matter which one you press, the lift still comes no matter what one you press, so why not just one button?

Also, does repeated pressing have any effect, except frustration?


 

another_someone

  • Guest
lifts, does pressing the buttons do anything?
« Reply #1 on: 23/11/2007 13:15:04 »
All depends on how the microprocessor in the lift is programmed.

Have recently heard about one lift (in a 42 storey building) where you press the button for which floor you wish to take the lift to before the lift arrives, the lifts then try to decide which exact lift would be most efficient to take you to that floor, and if you get into the wrong lift, you could end up 20 floors away from where you wanted to be.

For most lifts, where you choose the floor you want to go to after getting into the lift, it will depend on how the microprocessor prioritises other events (e.g. if you want to go up, but press the down button, but someone on the floor beneath you has also requested the lift - then when you get into the lift, and press a button for a floor above you, will the lift forget that someone on the floor beneath you also requested the lift, or will the lift go down one floor to pick up the person who requested the lift on that floor before satisfying your request for a floor above - this depends totally on the guy who programmed the lifts microprocessor, but common sense would indicate that if the lift was going down to the floor beneath you to service a request from someone there, and simply stopped on the way there to pick you up, then it should continue to go down even if you request for a floor above).

Ofcourse, for an infrequently used lift service, where there will be little contention, then these issues are unlikely to arise in practice.  Similarly, if there is only one lift, then even if the lift does continue to go down, and even if that means it takes you on a longer journey, it wont make much difference in terms of overall time, since you would anyway have had to wait for the lift to return.  Where it will likely make a difference is where you have multiple lifts, and high levels of contention, so that you may be taken on a downward journey first, whereas another lift might have scheduled you for your upward journey, and would have saved you having to go down before going up.
 

lyner

  • Guest
lifts, does pressing the buttons do anything?
« Reply #2 on: 23/11/2007 17:13:50 »
I used a lift, recently, which forgot anyone had called it, once it had arrived at a destination - all the buttons were canceled. First on the button after that, got the lift.
 

The Naked Scientists Forum

lifts, does pressing the buttons do anything?
« Reply #2 on: 23/11/2007 17:13:50 »

 

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