Canceling out

Lookout

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Feb 2015
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Here is one of my practise questions I have for college-

Design a circuit that operates thus: When an input is activated it energises an internal relay. After a time delay of '2' seconds output 'A' is energised, followed by output 'B' 2 seconds after that, followed by output 'C' 2 seconds after that and finally output 'D' 2 seconds after that.

Here is my attempt so far
1zbgrx3.jpg
http://i60.tinypic.com/1zbgrx3.jpg

What I need to know is where the internal relay is inserted and how do I cancel each output after it's lit (Output are lights)

Thanks

1zbgrx3.jpg
1zbgrx3.jpg
4
 
Maybe it's me, but I can't load your pictures. Try hitting "Go Advanced" below and attach the jpeg. Make sure you hit "Upload".
 
Internal relays may also be descrived as "virtual relays" - they don't physically exist. You cant touch them and you can't hear their contacts close when you energize them.

You're programming in what looks like RsLogix 500. In this case, you can use "B" file type for internal relays. You can also use "N" type.

Assuming you're using "B", replace the TON T4:0 with and OTE B3:0/0. Tou can use OTL, instead, if you want the internal relay to stay energized after the input turns off

But the TON on a new rung, but put an XIC B3:0/0 on the left of the rung.

This will get you started.
 
Sorry guys tried insert image via http but does not seem to work.

Yes its RSLogix 500

Cheers that's the internal relays sorted
http://i59.tinypic.com/24fbbzn.jpg

How do I make them cancel out each other out?

I've tried about 3 different ways but it doesnt seem to end up what is asking for :(
 
Last edited:
Design a circuit that operates thus: When an input is activated it energises an internal relay. After a time delay of '2' seconds output 'A' is energised, followed by output 'B' 2 seconds after that, followed by output 'C' 2 seconds after that and finally output 'D' 2 seconds after that.
Click to expand...

Looks as if the others are off line at the moment.

In you above statement you dont really specify how you want the outputs to turn off.

Should output A turn off when output B comes on and same for B when C comes on, and C when D comes on, and if so what to do with D at the end of the cycle? Should it go off after a certain amount of time?

Or is there another input we dont know about that should turn off the outputs?

Let us know and we will try to guide you to a solution.

BCS
 
Lookout said:
Sorry guys tried insert image via http but does not seem to work.

Yes its RSLogix 500

Cheers that's the internal relays sorted
http://i59.tinypic.com/24fbbzn.jpg

How do I make them canceled out each other out?

I've tried about 3 different ways but it doesnt seem to end up what is asking for :(
Click to expand...

What ways have you tried? I'm not sure I understand exactly what you want to do, but try putting an XIO O:0/1 on the same rung at the OTE for O:0/0. That will shut off O:0/0 when O:0/1 is on
 
I was told they must cancel each other out as the next question was-

Add to the previous program (the one I posted) so that as each light is lit it cancels the previous one. By making use of internal relays extended the program so that it will run continously until stopped by a second input.

I tried putting a XIO T4:0/DN before T4:1 thinking it would not be true until the timer was done but I was wrong.

Thanks for the quick replies on this btw, real time problem solving :)

-rguimond I tried that but it does not seem to shut off O:0/0
 
Lookout,

Although I cannot see your program, write down what you are trying to do.
step by step, then break the project into smaller pieces.
how do you start the logic?
what happens first, then what happens next. work your way through the logic
and then the last step would be how to turn off the lights.

create your program and zip it and attach to your post.
regards,
james
 
Want to impress your instructor? Use one timer and LIM instructions to turn on each light. You can use GEQ and LEQ instructions to achieve the same effect.


You could also use a sequencer SQO.
 
Here is a modified version of the file I mentioned in the earlier post. Just the values were changed.
 
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