learning...

hi everybody... ý am learning plc programming.. ý wrote some programs but ýt could not work continuously.. how can ý do it? that is, ýn simplier ý want to push a button and the light goes on forever...

serhan,

This could be an interesting thread, I bored and in a helpful mood so hear goes... there are many ways to skin a cat the simplist is based on 'relay logic.'

start Light
------[]-------------------------------()
| |
| light |
----[]----

This is called a hold-in unfortunately once turned on it cant be turned off so you need an off button

stop start light
-----[/]-------[]----------------------()
| |
| light |
----[]----

It can also be achieved by using a latch and other more complex ways. There is a link on the top of the page to "Learn PLCs" have a look, have a play and if you get stuck ask a question, but try to limit yourself to a specific issue. Do yourself a favour and don't ask for a traffic light program, Im not quite that bored....

Andrew

Originally posted by serhan
[B]...ýn simplier ý want to push a button and the light goes on forever... [/B]

Click to expand...

Simple, keep your finger on the button forever. beerchug

We have all been through this when we started.

Pierre, good one...y am still laughing.

Serhan, you have to "latch" the output. To clarify what corkers posted I have redone his drawings:
In this case the ouput itself creates a "latch" that holds the output on. As corker stated this cant be turned off once turned on so:
As you can see a "stop" or some means to "unlatch" the circuit is needed.

Pierre, good one...y am still laughing.

Click to expand...

Good one yourself, Ron.

I think you didin't understand me...

explaining....: I have a simple system such that there is a motor, plc....

ý want to control the motor with timer and start running clockwise for 15 seconds and after 15 seconds turn the opposite direction and run for 20 seconds...

after this 35 seconds I do not want to press push button again...

but

start light
----[]----+----------------------------( )
| |
| light |
----[]----+


this idea is not working here...




there must be something which press the start button secondly....

I hope you understood me... ))

Hello,

What do you wanna do, just make a blinker. Once pushed on the button
and the light keeps flashing on..off..on or a sequence you define?

Serhan,

when displaying a drawing it must be preceded by "[ ladder ]"
And when your done, on the next line place "[ / ladder ]"



This will allow the htm to hold the formatting.. spaces and shuch.

Note: when using these commands remove all spaces between the brackets.

Mike.