Omron lift program

Can anyone pls tell me some basic steps needed to program an omron plc to program a lift. I was given this project by my teacher and he wanted our group to program two lifts so that if someone presses a (up or down) button to call a lift, the nearest lift will reach that level first. The lifts can go to a height of 20 stories. We are still very new to plc programming and not sure how to start.

Starter for 10....

1) Decide on the Input/Outputs to the PLC.

i)1 position switch input for each floor , x2 elevator = 40
ii) Pushbuttons for Up/Down 2 x 20 x 2 = 40
iii) Outputs to Drive elevators Up and Down, 2 x2 = 4
iv) Analogue input for Floor selection in Elevator (use BCD input
Binary Coded Decimal) X2 = 2.


Is this helpful ?

Thank u for your assistance.

Hi

Nice problem!
Smersh is right when he say that the 1st setp is choose the I/O for your program.

i)1 position switch input for each floor , x2 elevator = 40
Input1, Input2, etc...
You may convert this information into 2 decimal variable with the number of the floor of each elevator.

ii) Pushbuttons for Up/Down 2 x 20 x 2 = 40
Funny 2 x 20 x 2 = 40 ?????
You need one Up and one Down buttons for floor, 2 x 20 =40
Again you may convert this info into one decimal variable with the floor number and one binary variable with the up or down.

iii) Outputs to Drive elevators Up and Down, 2 x2 = 4
No comment

iv) Analogue input for Floor selection in Elevator (use BCD input
Binary Coded Decimal) X2 = 2.
If you only want that the lift go to the right floor you can forget this part.

Step 2
When someane call the lift, the program make the difference (SUB) between the position of elevator 1 and the floor of the call and the diference between the elevator 2 and the floor of the call.
Then se the minor diference.

Try this

Hello,

Thanks 4 the tip but I am not quite sure about how to implement step2 into the program. How can i subtract the postion of the lift from the call? Do i need to add another input into the program to determine the floor where the call button was made?

The program need to now the floor of the call, but is not another input.
You need to put 2 buttons on each floor,
An small example if you put input_1, in the first floor for the up button and input_15 in the 15th floor, when input1 is on move the value 1 to the decimal memory call_floor, when input_15 is on move the value 15 to the decimal memory call_floor.

Thanx again, i'll try tis out.

If you want a really groovy program, you can use a reversible shift register to track where the lift is. (SFTR)
beerchug

Hi there
just this:
20 floors= 19 upcalls + 19 downcalls + 20 carcalls = 58 inputs
if you want people to now that there call is accepted
add 58 outputs for little lights in the call buttons
you could use encoder 2 phase one + up/down counter in PLC ?
for position control
I have to tell you, elevators control systems can be very very very
complicated (think of 8 lifts in one group what lift will anwser the call ??
worked 35 years in this bussines

sorry for bad spelling ENG. is not my basic lang.

Jeff

ABS(pushbutton - positionlift1) =distance1
ABS(pushbutton -positionlift2}=distance2
if distance2 < distance1 then sendlift2 else sendlift1
the rest is easy.
BTW if you do have a program show it to me and i will be of assistance however you should make the program.