What I want to do and what I can do....

I’m just a simple residential/commercial electrician(that came into the trade late in life) and trying to learn PLC on my own. I’ve got LogixPro from TheLearningpit.com, Allen-Bradley’s Micromentor, and A-B reference manual on micrologix 1000. I’ll be taking a basic PLC class this fall, but right now I’d like to more….a lot more!

Using the LogixPro and looking at the student exercises about cascading timers, I’ve put three cascading timers T4:0 T4:1 T4:2 and attached a DN bit on each rung were I have a light when timer times out. I’ve looped them, but what I’m trying to do is to turn off the output once the other timer starts…does it make sense

Rung0
I: 0/0 T4:2/DN |TON |
------] [----------------]/[---------- | timer T4:0 |
| time base 0.1 |
| preset 100 |
| acc 0 |

Rung1
T4:0/DN |TON |
------] [----------------------------- | timer T4:1 |
| time base 0.1 |
| preset 100 |
| acc 0 |

Rung2
T4:1/DN |TON |
------] [----------------------------- | timer T4:2 |
| time base 0.1 |
| preset 100 |
| acc 0 |
Rung3

T4:0/DN O:2/0
--------- ] [-------------------------------------( )

Rung4 T4:1/DN O:2/1
--------- ] [-------------------------------------( )

Rung5 T4:2/DN O:2/2
--------- ] [-------------------------------------( )

------------------------------------------END

(At this point all the outputs are on, and what I want to do is to turn O:2/0 off once T4:1 has timed out
and the same when T4:2 has timed out, and the same thing T4:0

Can anyone explain to me how to do it? I have no other reliable reference, I do better when I have a reference. This is no homework like I said, I’m learning on my own?
Another question? Does anybody has Phil’s book? I hate to buy something before I can see it! The ABRSLogix like the LogixPro format helps me a lot to learn how things work, and if his code is a bunch a numbers, like the on line tutorials it will be a little harder.

If i understand correctly, You want the light O:2/0 to be on only when T4:0 is timing, but not when the other two timers are timing, and the same for the other two lights??


A simple solution to this is to address the XIC's of rungs 3,4, and 5 with the Timer Timing bit instead of the done bit.....T4:0/TT, T4:1/TT, T4:2/TT

Try that out and post back....

Addendum

Addendum:
Maybe, parctice on drawing code with keyboad
or figure a better to my code in!

Thank you it works.
Let's see what other trouble I can get into.
What about Phil's book.
Maybe nest time I'll post the screen capture,a picture is worth a million words. thanks again

Try using /TT instead of /DN in the output rungs. The .TT bit is on ONLY when the timer is enabled yet not expired.

Think of how you would accomplish it with the timers you're used to using. The PLC just makes it a LOT easier! If you wired the lamp to the NC contacts of a regular timer that get power only when the timer gets powered. Works the same way...

-Eric