Need Help with Homework

I need help with homework just started class in PLC. Need to draw a ladder diagram with one on delay and one off delay timer for lighting controll.

Tom Her. said:

Need to draw a ladder diagram with one on delay and one off delay timer for lighting controll.

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Are they just giving you guys the website instead of a text book at school now?

What PLC are you using? I'll bet the timer functions will be relevant to this assignment.

I need to drive home from work today. I-894 gets me there and the freeway is really congested at 5pm. The brake pedal is on the left and the right is the gas. What do I do?

Logic

I will try to help you in your homework.
Can you describe the logic you want to write the ladder for it in words?
try to do so as a first step and then we will continue.
best luck.

Thank you for your reply I do have a text book will be using a Allen-Bradley MicroLogix if you can help me I would Thank You

Re: Re: Need Help with Homework

akreel said:

I need to drive home from work today. I-894 gets me there and the freeway is really congested at 5pm. The brake pedal is on the left and the right is the gas. What do I do?

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In order to assist you further with this application, what car/suv/truck are you driving and type of gas are you using?

To mesh Tom's and akreel's posts together: Start car/computer. Steer/move mouse to exit sign/button labelled "Learn PLCs" at top of map/screen. Hit brake pedal/click mouse button.

Akreel I'm with you. It seems the classes are using this forum as their textbook, which would be okay if they all turned to the Learn PLCs Chapter FIRST.

Well guys, I'm involved in vocational training. This means I'm training adults to learn in their professional life what most of them had better done while in school.

One of my main observations is that instead of learning people to think, nowadays some schools are teaching how their pupils can remain lazy and yet get their job done. In fact, some of them simply have made an art out of lazyness. Knowing some of the teachers involved in this process, I do not longer wonder how this is accomplished: those teachers are simply transferring their methods to their pupils. Last year I asked one of them why he was using Basic-stamps to teach the art of programming instead of Javelin-stamps. My reason for this question was the fact that Java is far more widely used, even in PLC's. This teacher answered me: why would I learn yet another language? I know for a fact, because I was in his class 25 years ago and had regular contacts with him, he has been teaching the same old stuff since 1978 and in those days he was regarded as progressive. But now he's outdated by at least 15 years.

Luckily there are still some so-called old-fashioned teachers around. I'm sure my fellow teachers/trainers on this forum are of this kind.

One word of caution for those who want to help this guy (and I don't mean the "old-timers", they know the routine): don't give him a fish, but learn him how to fish. It will help him a lot more in the end.

Regards,

Ya know, fellers, sometimes it iz so eazy t' take a swing at these kids it ain't even fun! There jist ani't no sport in it no more.

To all the people that replayed for my homework I just asked for a little help not for someone to do it for me. I thought this would be a good site to learn something but I see all it is a buntch of people that don't have anything to do but sit around and talk about how smart they THINK thay are!!! I will not come back to this site. To The person that wants to smack me I saw your picture and I can tell that I i'm much older and tougher than you look. Good bye TOM HER

Tom Her,

I think before you start trying to program your homework assignment you should re-read the instructions.

I'll bet the instructions do not direct you to use an On-Delay and an Off-Delay timer. Rather, I expect the assignment is to write a program to control a flashing light using two timers. One of the timers is to control how long the flashing light is ON, the other timer is to control how long the flashing light is OFF.

That's not to say that you couldn't do the assignment using two On-Delay timers or two Off-Delay timers or one of each. Just don't make it any more difficult than necessary.

The hardest part of an assignment like this is the tyranny of the blank sheet of paper. You know this is going to involve timers. Write a timing diagram of how you want the lamp to operate. Then go the the lab and learn how PLC timers function. Program some logic that you think will make the lamp operate the way you want it to. Try it out. If it doesn't work, the only damage is to your ego. Whether it works or not, try something different. Study the attempts that don't work until you understand why. Do the same for the programs that work. Remember, the point of the exercise is not to make a light blink. It's to help you understand ladder logic and the PLC's timer function.

well ... maybe I'm too late ... but anyway ...

first:

Greetings, jvdcande, and Steve Bailey,

well said ...


next:

Greetings, Tom Her.,

so let’s get started with your homework assignment ... first of all you didn’t give us much to work with ... “for lighting control” doesn’t tell us enough about how the program is supposed to function ... it would be a good idea to post again and tell us things like:

“when the switch is turned off, the lights should stay on for X seconds and then go off automatically” ...

it would also be a good idea to show us what you’ve already tried ... and tell us what your “solution” is doing wrong ... then we can help you learn ...

but just in case you’re TOTALLY lost ... or just in case your instructor didn’t give you any more to work with than you’ve already posted ... here’s a short program to play with ...

[attachment]

work through this and answer the following questions:

suppose that SWITCH_X has been OFF for a very long time ...
(1) is LAMP_A off or on? ...
(2) is LAMP_B off or on? ...
now suppose that SWITCH_X is turned ON and left ON for a very long time ...
(3) describe the reaction of LAMP_A ...
(4) describe the reaction of LAMP_B ...

next suppose that SWITCH_Y has been ON for a very long time ...
(5) is LAMP_C off or on? ...
(6) is LAMP_D off or on? ...
now suppose that SWITCH_Y is turned OFF and left OFF for a very long time ...
(7) describe the reaction of LAMP_C ...
(8) describe the reaction of LAMP_D ...

if you need help with the timer instructions, look them up in this book:

Instruction Set Reference Manual

this little exercise should go a long way towards squeezing the educational “juice” out of your homework assignment ... here’s a pretty safe bet: your instructor doesn’t really care about how well you can control a couple of lights ... what he’s trying to do is encourage you to learn about how the timers operate ...

anyway, here’s a suggested plan of attack ... post some more details about the requirements of your assignment – and tell us what you’ve tried so far ... OR ... post your answers to the questions above ... OR ... to get the most bang for your buck – do BOTH ...

if it seems like you’ve just been getting a lot of harassment and little or no assistance, it’s because what you’ve posted so far makes it LOOK LIKE (and maybe we’re wrong here) ... but it looks like you’re asking us to do your homework for you ... that’s a big “no-no” on this forum ... basic idea: you work – we help ... how you choose to respond next will tell us quite a lot about whether you really want to LEARN something from this little assignment ... or if you just want to receive a passing grade ...

and incidentally, welcome aboard ...

Re: Re: Re: Need Help with Homework

format C: said:

In order to assist you further with this application, what car/suv/truck are you driving and type of gas are you using?

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The specifications are still open. What would you recommend? I did find out one more piece of information: we drive on the right side of the road.

You don't need help

Tom her
I tried to help you

I will try to help you in your homework.

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I tried to let you think ,i tried to let you learn the first step in writing ladder ,i tried to let you do like most of this forum members do(Most of the members here are really smart and you are not the person who will evaluate them),i tried to teach you how to be well organized but you didn't give a postive responce.
blame your self ,don't blame the others
You really want us to do your homework ,you want us to give you what you want and when we refuse you made like a child we didn't gave him his toy.
and know you are happy because Steve &Ron give you what you want.
Ok take it without any effort from ,may be you will get the full mark and pass your exams in the end of the year.
but take care if you used to do so you will not success in your practical live
Best luck

Tom Her. said:

I need help with homework just started class in PLC. Need to draw a ladder diagram with one on delay and one off delay timer for lighting controll.

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By the way, this is a statement, not a question. Therefore, no answer is required...

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Back to the important stuff...

Originally posted by akreel
I did find out one more piece of information: we drive on the right side of the road

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Then you'll want to use the Car Shift Right (CSR) bit...

beerchug

-Eric

Tom Her. said:

I will not come back to this site. To The person that wants to smack me I saw your picture and I can tell that I i'm much older and tougher than you look. Good bye TOM HER

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Tom, I think he's talking to you! Watch out..he's got your photo and name!

Ron, I commend your valant attempt a the education of Mr. Her, but I think your now teaching to an empty class room.

So much for that question....