How PLC control an elevator?


Thread Starter



I'm a student currently doing a project for my final year on PLC controlling an elevator. I'm currently using Siemens S5-95U PLC. What i have to do is write a ladder logic program to control the elevator. At the moment, i dont have any idea how to write the program because i don't know how the elevator works with PLC.

I need help on the information as follow or any website i can refer to. If possible, i can have the ladder logic program on elevator which i can
refer to also. I will put it under reference on my thesis.

P.S. I already looked at the thread The dreaded elevator program at and is different from what i wanted.

Best regards,

Hello Kim my name is Dave and i'm a elevator technicus in Belgium. I have writen a program also for an elevator but for a mitsubishi PLC. Do you have to make a elevator in real?? or just the program ??

Mail me to to following address it's easier
"[email protected]", mailto:[email protected]

With regards

Hakan Ozevin

Dear Kim,
Just observe an elevator near to you and try to learn how it works. This will
give you an idea and the main point of making a project is investigating it.
However it will not be enough; find the manufacturer of this elevator and try to find the safety concerns and sensors that makes this elevator work (If they do not want to give these details, be persistent; blackmail them if necessary :)).
It will not be enough still; you have to test your program as a simulation and/or in real application. These are what we are doing while generating an automation software. If you can do these steps, then your project is successful.
Then, you are an engineer, boy!
> I'm a student currently doing a project for my final year on PLC
> controlling an elevator.
> P.S. I already looked at the thread The dreaded elevator program at
> and is different from
> what i wanted.

But you should be able to adapt it to what you need?

Anyway, 1) you don't give us enough specific information to be able to help you beyond what's already in the archives, and 2) if we do your homework for you, how will you learn?

As in all problems - work out what the possible states of the elevator are, and decide what it should do in each state and how it'll move between them. Then translate that description into ladder.

Jiri Baum <[email protected]>
MAT LinuxPLC project --- --- Machine Automation Tools

Vitor Finkel


If this is purely an academic work, OR if the elevator does not carries passengers, I think it is OK to run it with a PLC on control.

If human passengers are allowed in the elevator, safety reasons request you to use a fail-safe control, such as relays, or a fail-safe PLC. A
Standard PLC should not IMHO be used where malfunctions may threaten people's life.

Several years ago I saw a kind of "internal bulletin" of "Allen-Bradley"
notifying their representatives not to sell PLCs for elevator control, but rather address the matter to ... at extension number such-and such.

BTW, all relays used in the critical path to energize the main elevator motors and door motor control should be "life-saving" certified, with
carbon contacts (never stuck in by short-circuit soldering) and gravity dropping (no dangerous spring failures).


Vitor Finkel [email protected]
P.O. Box 16061 Tel (+55) 21 2285-5641
22221.971 Rio de Janeiro Brazil Fax (+55) 21 2205-3339

Johan Bengtsson

I don't really understand your problem.
In what area is your problem:

1. How the signals from sensors and buttons appear in the PLC
2. How you command the motor to start moving from inside the PLC
3. How to connect the elevator to the PLC
4. How to program the PLC (making any PLC program)
5. How to make a PLC program suitable for the elevator
6. Something other

/Johan Bengtsson

Do you need education in the area of automation?
P&L, Innovation in training
Box 252, S-281 23 H{ssleholm SWEDEN
Tel: +46 451 49 460, Fax: +46 451 89 833
E-mail: [email protected]
We at greenland intelligent systems at cochin kerala india have developed both a control systems for elevator using plc and also a ladderlogic for basic 4 floor operation.

contact us at [email protected] for further details