Please Help Using One Shots

[bryan372002]

Here is what I came up with and does exactly what the instructor wants, would appreciate any evaluation,as in poor programming techniques, ect.


Thanks For all the help

 

[PeterW]

when I was in college, years ago, they taught us to make logic formulas and then simplify them, leaving simple logic to code.

 

[Clay B.]

Well what you have there could be done in 2 rungs and you would not break the Output rule. Combine your latch lines together and do the same on your unlatch lines. Now you have 2 rungs doing what you are doing with 4. Look at it again working the logic thru you head. You may come up with something even shorter.

Programing is like painting, everybody has a different brush stroke.

Also vague instructions are a big part of this because most people that ask us to write code have no idea what they are asking for.

 

[geniusintraining]

Hell Bryan everyone else gave it to ya...so here, this is what Clay is talking about...I just dont understand how he counts , I see two rungs and you can drop it down to one, but maybe thats the glass half full/empty thing...

 

[Terry Woods]

This is all insane...

"Spec-Analysis", man!

The entire problem, Non-Reverse and Reverse, can be handled with only two rungs... just as soon as there is a reasonable spec!

Bryan said to Lancie...

"Sorry to have caused so much confusion, but this site is called PLCS.NET Your personal tutor site."

Gee, Lancie... I wonder... how does that feel? Does that wear well on you?

To which, Lancie replied...

"What you are saying then is that the description can be intrepreted any way your instructor wants. It could mean "go catch a cat and twist it's tail". In this case I can't help you much.

With a clear description, I can make it do whatever is necesssary."

Gee again, Lancie... isn't that exactly what I said?

Using English might not be as good as telepathic communication... but, stand-by... here's a flash... it is the only means we English speakers have!

And so, we, the readers, have NO CHOICE but to interpret, as accurately as possible, the specifications as they are written!

And that is exactly what I did with what you called my "...so far off in left field that I do not know how to answer! What are you smoking?" analysis.

If you took the time... you would have seen... clearly seen... that my initial point was well founded. After all... in the end... you said the same thing! But not before... "impuning my integrity" (Rice, before Congress). snort...

All of that aside... the REAL fault lays with that so-called instructor.

Bryan... I really wish you would post his E-Mail Address... I PROMISE, ON MY FATHER'S EYES (my Mother is dead), we won't mention your name!

By the way... at the very least, just in case we run into "this" later... what is his name?

OMG!... Could it possibly be someone that we, the "irregulars", actually "know"?

None the less, Bryan... the ENTIRE project can be handled in 2-Rungs!

The first Rung would be the "cause" to GO OFF.
The second Rung would be the "cause" to BE ON.

Geez... could someone PLEASE provide a decent set of specs???

 

[rsdoran]

I have no idea who the fault lies with and definitely have no idea what that style of programming would represent i.e. when the REVERSING switch is not true then what happens? The light going to burn in reverse?

I have posted a couple of times but deleted them. I did not think Terry could be far off base because Lancie, you never got on any base either....just threw things out there based on what you were interpreting.

bryan Post 1: I put the OSR in the rung between my input (switch) and my output (light)and labeled it B3:3/1

Alaric appropriately explained one-shots.

bryan Post 3: if input 1 and 2 are true then output 1 will be off and remain off until input 3 is turned on, output 1 will remain on after input 3 is turned off as long as input 1 aand 2 are true

Alaric again provided a solution that normally would be appropriate for that statement i.e a standard seal in ckt.

bryan Post 7: Yes I have used the common seal in circuit, but the trick is, when inputs 1 and 2 turn the light off, it has to stay off until input 3 is made, reagrdless of the state of inputs 1 and 2.

Originally it was stated input 1 and 2 must be true, now it is regardless of their state.

bryan Post 8: ok here is the part of the project that are stumping me. there is actually 2 parts to this but the first part I have I think

1. when inputs 1 and 2 are on then output 1 will be on and remain on after either input 1 or 2 are turned off. the only way to turn output 1 off after it is on is to turn input 3 on, if inputs 1, 2, and 3 are on then output 1 will be on. (this part I got)
2. add a reverse switch to your program so that when it is true the program will work as follows.
3. when inputs 1 and 2 are turned on output 1 will be off and remain off until input 3 is made, output 1 will remain on after input 3 is turned off as long as inputs 1 and 2 are on.

Every statement contradicts a prior statement, more or less.

I think originally the ckt was a standard seal in ckt but the instructor later wanted him to add a "reverse" switch that when true would make the ckt work opposite of original....this is definitely open too interpretation but I think it is closer than anything offered so far....including the code that bryan stated was what the instructor wanted, that code makes no sense at all.

After this point it gets too convoluted too follow accurately, which is why I have deleted my previous posts.

 

[geniusintraining]

I think the instructor is seeing if he can get one over on PLCS.net…he’s watching our every move…

Later he will add the forward circuit, then a HSC or toggle

 

[Steve Bailey]

I'm not sure how Bryan can claim that his solution does everything the instructor wants. The output can't be turned on unless the reversing switch is true.

Bryan, are you giving the specs based on what you heard the instructor say or do you have a written spec from him? It almost sounds like the instructor is reinterpreting the specs in order to get the ladder logic he wants.

 

[bryan372002]

Yes You are correct Steve I did not include the part of the rung (branch) that turns the output on if the reverse switch is not made.


Yes I have written specs and I will copy and post them word for word, and yes i did have to clarify what the instructor wanted as opposed to what was written.

 

[Lancie1]

Yes I have written specs and I will copy and post them word for word, and yes i did have to clarify what the instructor wanted as opposed to what was written.

Now we see the problem. You are reinterpreting what the instructor wants. I think it is you that does not understand the problem. It is likly that you have misintreprted the problem and there really is something missing.

If the gven information is accurate, then the question has two parts and we have to assume that it is the same circuit in both parts, except for the Reversing switch. What does the "Reverse switch" do? Does it reverse the Output? No, it merely reverses the function of the Inputs.

______Turning On____Turning Off
Part 1.....In1&In 2........In 3
Part 2.....In3...............In 1 or In 2

Assuming some symmetry in the GIVEN INFORMATION (most real-world problems do have symmetry), it would be illogical for either set of inputs to take on BOTH Start and Stop roles in the two different parts of the problem.

Terry and Ron, you are trying to read things into the problem that are not present. Part 2 does not say that Inputs 1 and 2 have to turn on Output 1. You are reading something in here that is not there. In Part 2, the problem only says that if Inputs 1 and 2 are on, the output is off. Period.

Bryan, I suspect that you are speaking for your instructor here, in an attempt to save time. You are assuming that you know what the man would have said, so you are going ahead and stating it as fact, without ever actually checking. It will be hard to help you until you come clean and tell us the whole truth.

 

[Clay B.]

Geniusintraining,

I did see that it could be reduced to one line but I was leaving that for him. I was just cringing at the double output usage. The sadistic side of me would have liked to have seen what would have happened but the side that pays the bills says that could be an expensive show in the real world

 

[Lancie1]

I'm not sure how Bryan can claim that his solution does everything the instructor wants. The output can't be turned on unless the reversing switch is true.

Steve, good call.

Bryan says that my circuit doesn't work, but his is exactly what the instructor wanted. Yet anyone even halfway familar with ladder logic can see that it is, at best, only ONE HALF, the second part, of the problem.

The entire Part 1 condition of when the Reverse switch is OFF, was conveniently ignored!

Methinks we are being played with here. I have better things to do.

 

[Lancie1]

Using English might not be as good as telepathic communication... but, stand-by... here's a flash... it is the only means we English speakers have!

Terry, I believe I said word descriptions. I meant as opposed to mathematical and Boolean logic descriptions. Those would be more precise, as an old K-map man like you should appreciate.

The whole problem here is that Bryan is trying to interpret some problem and then restate it (incorrectly). I don't know why he thinks it is necessary for him to do that. Possibly he is trying to disguise his homework problem so that his instructor will not recognize that he received help with it. He should know that many of them hang out here and will not be fooled by such shenaigans.

For all Bryan knows, I may BE his instructor in disguise!

 

[Lancie1]

Bryan, you said:

when switch 1 and 2 are turned on light 1 will be off ( so do you assume that light 1 was on from startup?)

No,No, No, this is where you are screwing up. Why assume anything here? Take this statement at face value: When switch 1 and 2 are turned on, light 1 is not on. Check you logic to make sure Light 1 is off if Switch 1&2 are on. That's it, now go on to the next statement.

 

[rsdoran]

Which statement would that be? I am not reading anything into anything, the statements are contradictory.

As I stated the first statement made sense:

if input 1 and 2 are true then output 1 will be off and remain off until input 3 is turned on, output 1 will remain on after input 3 is turned off as long as input 1 aand 2 are true

This is easy.

After that point things change. What gets me is you state you KNOW what is being said but also state things like "I can not help" or "Methinks we are being played with here."

There is more but I am letting it go.