Modicon 984

Today I have been re-assured that with the Modicon 984 and Proworks,
you can accually energize and de-energize an output with a single input using only two lines/rung of logic and no tools, strictly coils and contacts. I've played arround with this for awhile and can't seen to get it working 100% is there something I am missing with the scan time in this PLC or can this accually be done at all, just curious cause its bothering me that I cant figure it out.

Thanx.
Shane

Well, today I am programming a 984 for the first time, ever.

You problem would be a good excercise for me to get my head around it, if I can understand what you want to do.

Are you trying to toggle the output?

Doug

You know shane, you can REPLY to a thread, you don't have to start a new one. You never gave any feedback to your original post, in which we told you exactly how to do it (in many ways).

Now that you've enlightened us with what brand PLC you're using, perhaps Doug can help you with the specifics for doing it in a Modicon.

Doug, see THIS THREAD to catch up.

beerchug

-Eric

Eric quoth thus-ly
"Doug, see THIS THREAD to catch up."


Yes, I just noticed it.

Thanks,

Doug

Shane

Eric&Doug just gang on you.Your lucky that I think I understand your problem.
What I found out that start stop with one push button is not work with Modicon as it work with other PLCs.It took me a lot of time to know why.I not sure but I think Modicon scan the program different then other PLCs.It happened before many years 7-8 years, it sound stupid I "risk" my reputation when I say something like that.
But when I changed the contact order it worked.
What I remember that the Modicon scan every network not in ROWS like most of PLCs he scan the program in COLUMNS.
Go to your Modicon book and read this chapter.
Maybe one of our friends in this forum can explain it better then me.
My English is not good enough for that.I had only 3 project with Modicom.and I dont have that file here at home.I dont have DOS on this PC .I will look for that tomorrow when I will be at office.
I curious too
All the best

984 Ladder Logic

The trick is to use the advantage of the Modicon 984 Ladder Logic "top to bottom, left to right" logic solving sequence.

I hate to give you your entire homework answer but here I go. This is a only possible solution. Pay attention to the column placement of the logic elements.

----]P[-|-------]/[---------------()---

        |

----] [-|-------]P[--------] [----()---