Four way junction traffic light ladder logic

[hakeemrazak]

Hi. Does anyone have a traffic light program as stated above? Your help would be greatly appreciated. Thanks

 

[RussB]

You will not learn properly if your homework is done for you.

 

[Eric Nelson]

Ah, the ol' traffic light assignment...

-Eric

Oh, and to answer your question... No

 

[RheinhardtP]

Here you go

 

[shooter]

all above have done this.

make a stepper in ladder
essence is when time and step active then next step active. reset last one.


step1 all red
step2 left green rest red
etc.

 

[shooter]

btw yes we all have this program, but you will have to tell which plc you are using and what language like ladderor sfc or fbd.

 

[hakeemrazak]

Arrangement is a four way junction, North-South and East-West. I have been asked to ladder program it using Allen Bradley Micrologix software. So far the outputs should be as follows:

Red, Amber and Green for N-S & Red, Amber and Green for E-W

 

[RussB]

Arrangement is a four way junction, North-South and East-West. I have been asked to ladder program it using Allen Bradley Micrologix software. So far the outputs should be as follows:

Red, Amber and Green for N-S & Red, Amber and Green for E-W

You will kill someone if they are all the same color at the same time!
May I suggest:
Red, Amber-Off and Green for N-S & Green, Amber and Red for E-W, then switch every 45-75 seconds.

 

[hakeemrazak]

Hahaha! Thanks for pointing that out. Obviously I meant it that way! Ive been referring to this website for my problem and im confused with the 'states'. I thought it only consists of inputs and outputs. Sorry to trouble anyone. I am very weak in this module

 

[hakeemrazak]

http://engineeronadisk.com/V2/book_PLC/engineeronadisk-85.html

The website i was talking about in the previous post

 

[iant]

http://engineeronadisk.com/V2/book_PLC/engineeronadisk-85.html

The website i was talking about in the previous post

by now you must realise that this is a common student question
it has literally hundreds of posts on this site.

NOONE here will do this for you.
so start doing the work and post your ZIPPED code so people will assist you.
OR
search this site for your answers.
the Photo of the traffic light tree has been posted before - I downloded a coppy it is a classic.

So sorry but you are obviously learning - start trying to learn.

 

[jvdcande]

Hi. Does anyone have a traffic light program as stated above? Your help would be greatly appreciated. Thanks

Long time ago (when I was still naive and thought giving the solution meant helping folks) I posted a Grafcet schedule for this kind of problem.

Now you have to help yourself by using the search function on this site, something you should have done to start with.

 

[shooter]

he answered with a very good html book, so wip (work in peace)
if you have a direct question just ask.

 

[Manglemender]

We were all novices once.

Good software always starts with a design. The best advice I can offer is to start with a pencil and a piece of paper and draw a flow chart that represents a solution. Each box in the flowchart represents a "State" and each connecting line between boxes represents a "Transition". Once you have completed this stage, post your results and people here will be able to advise whether it looks correct or where it might not be right.

Once you have completed the design phase then you can worry about how to write code.

Good luck,

Nick

 

[Lancie1]

Good, you know what PLC outputs you need to control.
PLC Outputs:
N&S Red, 12 secs.
N&S Amber, 3 secs.
N&S Green, 12 secs.
E&W Red, 12 secs.
E&W Amber, 3 secs.
E&W Green, 12 secs.

Now PLC inputs or controls do you have to use?

Suggestion: 1 TON timer, set for the total cycle time of all 6 traffic lights.

Procedure: Insert 6 rungs into a new MicroLogix program, one OTE output for each of the abouve lights. Once you get that, you may insert 1 more rung with a 27-second TON timer. Now you are ready to figure out how to use the timer to control the 6 oututs.