Studio 5000 3 floor elevator

[drbitboy]

From the assignment it looks to me like there is a trainer with a conveyor belt and bi-directional motor, three object sensor inputs (photoeyes maybe?), three pusher outputs downstream of the sensors, and maybe some other I/O.

My guess was that the assignment uses the various I/O on the conveyor trainer system to emulate an elevator: the object sensors emulate the floor indication inputs; one or all of the pushers model the door motors; the conveyor motor models the up/down motors, etc. I don't know what is used to emulate the in-car push buttons, but I don't think there is enough I/O left over for the on-floor, car-external call buttons.

just sayin'

 

[parky]

Yes I think you are right after reading the spec, I should have read it with a bit more care, it was an assumption this was an actual elevator, however, it will still need two buttons on the middle floor to decide which way to go (if they are simulating a lift) There are a number of scenario's that could happen that are not well documented.
If this is a simulated passenger lift, then the middle floor would need two buttons to call it.
It does not say that each floor has buttons to select another floor i.e. it only mentions buttons to choose floor (is this just for an operator on the ground floor ?).
If it is not a passenger lift then the outer doors on each floor will be manual so that when the lift reaches a floor the motorised doors open but the manual doors need to be opened to gain access, safety is required for non passenger lifts for operators to enter lift to put in or extract contents.
i.e. regardless of the position of the motorised doors if the outer door is not shut then it cannot move. I think as an example it is rather poor, teaching something that could not be put into practice is a bad idea, ok, it is only an excercise, but it is something that the students need to question.
What happens when a student graduates, gets a job, writes a program for some machine, someone gets hurt, "That is what I was taught at colledge" is no excuse.
One really good example of this is in my early days, although I was already a TV engineer, I attended colledge on an advanced Colour theory & servicing course (not that I needed it but company policy) only two of us had been actually in the game for some time, I asked if the power sockets were isolated by a transformer, the lecturer said oh yes I forgot to mention that, in the field, there are none, originally TV's had no earth, were isolated by the cabinet, depending on the type of power supply the metal chassis could be live (depending on the wires being connected in the plug the right way or not), this is where you have to be careful, in a workshop isolation transformers are used, the chassis was on older systems tied to neutral, some with SMP's could have minus 300v compared to earth. Omitting critical things like this in lecturing is often too frequent & it must be assumed that students will not have this knowledge.