Linked by Eugenia Loli on Mon 9th Oct 2006 01:31 UTC
QNX Most people haven't heard of QNX Software, though they've likely come in contact with it. The real-time operating system is used where software failure can lead to catastrophic consequences, even death - from high-speed trains to air traffic control towers to highway toll systems. It's also used in more than 100 different types of cars on the road.
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great stuff
by Sphinx on Mon 9th Oct 2006 04:09 UTC
Sphinx
Member since:
2005-07-09

Wouldn't get on an elevator with anything else.

Reply Score: 1

RE: great stuff
by JonathanBThompson on Mon 9th Oct 2006 00:51 in reply to "great stuff"
JonathanBThompson Member since:
2006-05-26

As amazing as this seems, it is entirely feasible to have elevators with absolutely no computer hardware or software involved: most elevators you use have zero computer hardware involved, in fact. It is very simple (comparatively speaking) to build decent elevators that are very reliable with zero computer stuff, as there's many ways it can be done with simpler electromechanical hardware.

So, if you maintain "Wouldn't get on an elevator with anything else." I hope you live in a place where you can easily take stairs up and down to whatever floors you need ;)

Reply Parent Score: 1

RE[2]: great stuff
by mipeligro on Mon 9th Oct 2006 08:01 in reply to "RE: great stuff"
mipeligro Member since:
2006-06-03

I think that in situations where there are a small number of elevators this is still true to a certain extent, but more and more, any situation in which there are more than 3 or 4 elevators in the core, is likely to have a traffic control computer coordinating all of the elevators.

After all, how else can they all be on the wrong floor, going in the wrong direction, when you need one? ;)

Reply Parent Score: 2

RE[2]: great stuff
by gfx1 on Mon 9th Oct 2006 14:38 in reply to "RE: great stuff"
gfx1 Member since:
2006-01-20

As amazing as this seems, it is entirely feasible to have elevators with absolutely no computer hardware or software involved: most elevators you use have zero computer hardware involved, in fact. It is very simple (comparatively speaking) to build decent elevators that are very reliable with zero computer stuff, as there's many ways it can be done with simpler electromechanical hardware.

Most modern elevators use microcontrollers, we had some old ones at work who were relais based (open rack with clicking things alover) quite relyable. but they don't live forever...
Modern ones include things like automatic leveling, smoother rides and in larger buildings some clever behaviour of the elevators can be usefull.
Using Microcontrollers with a couple of input, outputs
and a program saves a lot of additional wires and relais.

Reply Parent Score: 1

RE[3]: great stuff
by monkeyhead on Mon 9th Oct 2006 15:22 in reply to "RE: great stuff"
monkeyhead Member since:
2005-07-11

I can't imagine an elavator in a large building that didn't use a microcontroller or PLC.

How do you get your electromechanically controlled elevator to look at 10 requests from 10 different floors for up or down direction and schedule them appropriately with hardwired relays?

I'm sure it's possible with lots and lots of boolean simplification and cabinets full of hundreds of relays, but each relay is a mechanical failure point, and the project would be ridiculously expensive. I can buy 3 or 4 relays for the same price as a cheap PLC that can emulate thousands of relays.

Reply Parent Score: 3