2 traffic light station

hi folks, i'm kinda new in plc i need help in traffic lights if i have 2 traffic light stations


1 2
for 3 Sec Red red
10 sec Green Red
5 sec Yellow Red
3sec Red Red
10SEC red Green
5sec Red Yellow

after yellow loop need to be continue

Jessica

I'm gonna make a suggestion to help you out. SEARCH this site to find info that has already been given on your situation. Believe me you don't want to start this traffic light thing up again. But before that, Phil gives you 60 minutes to edit your post; Take a minute and edit your post---all of it! Quick.

Seriously-search this site. All your questions have already been answered.

Good hunting.

In my opinion, your times are unrealistically short. Ten seconds of green is only long enough to permit one or two vehicles to pass through the intersection each cycle. Furthermore, with three seconds of red/red and five seconds of yellow/red, for 44.44% of the cycle it's illegal to move. In other words, a device that is supposed to streamline the flow of traffic halts all traffic flow for nearly half of the time. You're going to have some seriously negative feedback from your customers.

If this is response to a specification from a municipality or Provincial authority, I suggest you decline to quote on this job. The Engineer responsble for writing the spec is obviously a political hack, unqualified for the position. As such, he/she will never be satisfied with your work, and when the inevitable brown fecal matter hits the fan will find a way to blame everything on you. As a result you will forfeit any profit you might make on the job and your reputation will suffer.

As difficult as it may be, somtimes you just have to walk away from a gig.

Steve,

I would bet (not much) that this is a student project.

jessica

When I got this assignment, we actually had to study an intersection to get data on traffic flow, average speed in both directions etc..That data was used to figure out the timing for the Red/Yellow/Green lights in either direction. As it turned out the timing for each direction turnd out to be very different because the expierenced traffic on the two streets was vastly different. The timing also changed at different times of the day due to changing traffic load etc..

It all depends of the scope of the assignment. For me the "traffic light" part if the problem was easy. The assignment actually delt more with the traffic audit, and "engineering economics" aspect of the placment of the light.

Therefore I cannot answer your question with the data provided. However as Steve said, in other words you need a top fuel dragster to get through your proposed light times.

Mike.

Uh, Mike... Though relevant, I think Steve was being facetious...
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beerchug

-Eric

I dunno Mike,

Since Jessica never actually asked a question, I just sorta figured that she was looking for a review of the information she posted. She said she was new at PLCs, but she didn't say anything about being a student. You think she was looking for somebody to do her homework for her?

guys its only a assignment my first traffic light assignment on timers i thought u guys are genius will get me outta this n let me learn with ur experince plz help me get through this
1 station 2nd station

and i got only 2 cars on oposite corners
for 3 Sec Red red
10 sec Green Red
5 sec Yellow Red
3sec Red Red
10SEC red Green
5sec Red Yellow

after yellow loop need to be continue

Jessie, Jessie, Jessie.....

Have you tried looking at the Menu at the top "Learn PLC's"

Have you searched the site for "traffic lights"

This topic has been covered a gazillion times....

Why do you beat around the bush, just come out and say whats on your mind..."I have this traffic light problem...Could some one do my assignment for me and email me the solution"....You will get the same response as in the previous posts until you show a little effort. But at least you are being honest..

Sleepy Wombat said:

This topic has been covered a gazillion times....

Click to expand...

I just counted... It's up to a gazillion and one now...

She seems to be getting desperate. How many others (besides Steve of course) received this?
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Do as Sleepy said, Jessica. Click on the 'search' icon above. Hint: It looks just like this:



When you get there, type in "traffic light". I just checked, and there are SIXTY-TWO THREADS with the words "traffic light" in them. Yes, one of them is indeed this thread, but that still leaves 61 for you to read. Once you've finished, you will (hopefully) understand why you are getting sarcastic remarks to your question.

We are more than glad to help students here, but the students have to make an effort first... :nodi:

Effort ef-fort (noun) - Earnest and conscientious activity intended to do or accomplish something

You have not...

beerchug

-Eric

What do you do when emergency vehicles come with their special light changing remote control?

I dont get it? Whats so hard about a traffic light any way???

Jessica, Try showing us your proposed code. Do something anyway!

elevmike said:

I dont get it? Whats so hard about a traffic light any way???

Click to expand...

That's a rather arrogant answer!

Perhaps you should cast your mind back to when you were very first introduced to PLC's (or even PC programming for that matter), I bet any money you like, that given a traffic light program to write, you wouldn't have been able to do it!

Nothing's hard when you know how to do it!

Paul

jessica said:

i thought u guys are genius ...

Click to expand...

Flattery - hey, it was worth a shot, eh?

jessica said:

...let me learn with ur experince...

Click to expand...

The two are mutually exclusive. You'd make more of an impression too if your spelling and punctuation improved. But, anyway...

Here's something useful. Gather up all your inputs and all your outputs. Now, write on paper, or the electronic equivalent, if you prefer, what must happen first. Make a few notes under this concerning what I/O might need to be involved. Next, write down how and why this first thing comes to an end. Do the I/O thing again. Then, write down what happens next. Do the I/O thing again. Then, what happens after that. And so on, and so on.

Build in your mind a detailed idea of what you need to tell the PLC to do. Repeat the process above 'til you think it'll work in the machine. Once you've got this, load your idea into the PLC, run it and find all the errors you made. Correct these and you're done.

Paul,

Your right my message was rather arrogant, wasnt it...

I guess I'm arrogant because I took the time in class to listen to the instructor, take notes, and read my text books etc..

There was no internet forums, etc at the time to assit me.

I would think that if this problem has been assigned, then the basics have been covered in the class. So she should be ready to write some code. If Jessica would just show a little effort, and do the basics she might be able to come up with some code. Then I would glad to advise.

A traffic ligh is very basic. It's like they made traffic lights so they could have this assignment.

The true goal of education is not to train like a rat, or dog, but to teach problem solving. When Jessica is sprung out on the real world she will have to solve problems that she never encountered in school.

She is being tained in problem solving. You learn by doing.

Regards, Mike

I tried to warn her...really.