Need tutor for help with plc/ladder logic related class

jessedurr said:

I only have access to the software when ever I am at school. That’s one of the reasons I am trying to find a simulator at home so that I can practice, build, and learn more during my free time and not just at school.

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From the sounds of it, you don't have much, if any time to learn a new piece of software, as you've fallen too far behind. However, I'll try to help anyway. If you cannot find an RSLogix emulator to use, then a fall back solution would be TwinCAT or CodeSys. You can be up and running PLC code on your laptop in a matter of minutes. Download and install TwinCAT for free (XAE, the first download link). You can then write and run PLC code on your laptop (simulator). No, it's not RSLogix, but it's at least something for you to learn PLC ladder code and how it works, and it's all I've got for you. The good news is that ladder logic is ladder logic. It's all the same. Learning the underlying mechanisms of how the PLC code executes is most important right now, as DrBitBoy said.

Personal rant to the school and PLC instructor/s:
I'd be more than pee'd off if any course required software to learn and do homework, but the software was only available for use at the school. That in itself is BS and a complete failure of the school and the instructor - FAIL!! If you are an instructor and want to teach PLC programming but cannot provide a particular software for each student to use remotely because it's not practical with that platform due to cost, etc.... then use a different platform to teach with where the student can access and use the software away from the classroom!!!

Personal advise to the student:
It's neither here nor there now, but I'll say it anyway - school has to be a commitment. If you want to succeed in the classroom, you have to make it a priority. Coasting through it will eventually catch up to you, and probably sooner rather than later. Hobbies and other stuff, even spending time with family and loved ones at times, have to take a back seat to your course work. The good news of that is that it's only temporary, until you finish school. I'm taking masters courses right now, one course per semester, and I commit 15-20 hours a week to it, outside of the classroom. That's a lot of time per week, but that's what it takes for me to keep up and succeed in these classes. Case in point - you have to put in whatever time and effort it takes to succeed in the classroom.

I like the assignment. It requires you to understand a lot of the fundamentals ie: how certain instructions work, forces you to convert decimal to binary etc.


This is all stuff that I assume he covered in class and perhaps you didn't pick up on or didn't think was necessary to know.


Either way, I think what you are looking for is someone to do your homework which I think doesn't help anyone in the grand scheme of things.


Why not start with telling us your understanding of the requirements of the assignment. IE what is the problem, what is it asking you to figure out? Can you at least take the first step? Then we can nudge you in the right direction.


From what I can see, you don't need software to figure this out. It is forcing you to read through and understand the fundamentals of how a PLC functions. This is one of the most critical skills to develop: debug code offline. This forces you to understand how the PLC program works.

PLCDontUQuitOnMe said:

From what I can see, you don't need software to figure this out. It is forcing you to read through and understand the fundamentals of how a PLC functions. This is one of the most critical skills to develop: debug code offline. This forces you to understand how the PLC program works.

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+∞

Let me extend that last sentence: "This forces you to understand how the PLC program wor;s, and if you do not understand then you will not succeed."

Watch that series of YouTube videos by Ron Beaufort: watch each one after the first repeatedly until you are confident you understand fully every word that Ron says, and everything you see on the screen. 90% of what you need is in the first two or three videos; the rest is understanding binary integers and how the TON Timer-ON-delay instruction works. Understanding Binary integers is easy once you understand that there is only one fundamental arithmetic operation: counting; all other operations (addition, subtraction, multiplication, division, etc.) are based on some variation or extension of counting.

If you get stuck, post here the link and time where you get stuck and maybe someone can flesh it out for you.

There is no other way to get there than to think like a PLC, and PLCs are not smart. You must discard all presuppostions and preconceptions and say "what will the PLC do with this instruction? What will it do if the input rung is False? What will it do if the input rung is True? What will it do if the input bit is 0? What will it do if the input bit is 1? What will it do if its input timer structure's .EN bit is 0? What will it do if its input timer structure's .EN bit is 1? Etc." It does not matter what you think it may do before you start, it does not matter what you want it to do before you start. The only things that will tell you what any instruction will do on any one scan are the states of its inputs and its input rung. And on the next scan those inputs may be different.

Do, or do not, there is no try.

You seem like you know what you’re talking about. Could tutor me for 40 an hour?

I never said I am looking for some one to do the work for me. As you can tell it is genuinely hard to find a tutor on the subject because none of you have called me or given me an hourly rate. I can not go to my class mates for help because they all either cheat or are in the same boat I am in. Either stop being judgmental or throw a rate at me so I can start working problems with you.

jessedurr said:

I need to know how to take a schematic like this and solve it for let’s say a run time of 5 seconds


By solve I mean determine which rungs are true and which ones are false after it has ran for 5 seconds


This is how the majority of my homework are. We use rslogix5000, ladderlogix, Allen Bradley, studio5000, and factorytalk. Those are the names of every program we have used in class/are currently using.

My phone number is 6362449459
I need some one who can tutor me for an hourly rate for an hour or two every week. Or maybe just once. I’m behind currently and in trade school when you get behind it’s not good. I really need some one who can help me catch up to where I need to be with this stuff. Catching up is genuinely my top priority right now. If any one knows a good simulator that I can use to run the type of programming the way I said above and can describe how to use it that would be genuinely helpful to me so that I can double check my work. I would be willing to pay money for help finding, setting up, and being taught how to use said simulator.

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I WANT A TUTOR. STOP SAYING I AM TRYING TO CHEAT. NONE OF YOU HAVE CALLED THE NUMBER. NONE OF YOU FULLY UNDERSTAND WHAT I NEED UNTIL YOU CALL THE NUMBER. SO STOP GENERALIZING AND MAKING ASSUMPTIONS. PLEASE CALL IF YOU CAN HELP.

I NEED a tutor. One of the reasons being I can’t even trust the grading system at my school because it seems to award cheaters over people who do their work. The last test we took 5 of the students used the simulator and got 100%. Every one who did it the way the teacher told us failed. The simulator isn’t even supposed to work!!!! My teacher has no clue how these other students are even using this damn thing but apparently what ever method they’re using is also being used by the jackass who makes these quizzes. One girl even took her paper up to the teacher and asked how she managed to fail the quiz only to find out she didn’t. She got all of the correct. Explain to me how I’m supposed to confidently learn in a environment like that?? I need some one who can work with me on my free time so that I can gain confidence in my work and ability to do this my self so that I can know for sure I am doing this right.
Currently all I do is go to school because I gave up on finding a job right now to focus on catching up. MY SCHEDULE IS COMPLETELY FREE OTHER THAN SCHOOL SO I AM FLEXIBLE. I go to night school 5:30-10:30 pm central time mom-thurs

I can't speak for anyone else on this forum but I can speak for myself. Our profession is a complex mix of disciplines that cannot be mastered without paying your dues. It starts out with a digital electronics background, some math, and some understanding as to how computers work. If you haven't got time for that and you want to be taught how to press keys and do mouse clicks on a particular Allen Bradley software product then go to Allen Bradley training.

The Ron B training that was recommended would be another place to start. I've got some PLC training that I do - but I'm not about to teach you how to operate anybody's software. It's like being a true operating engineer - once you've got the 'hands' you can quickly get up to speed on a Case or a Bobcat or a John Deere backhoe. If you don't have the hands you can't run anybody's equipment. You get the hands by paying your dues and that process can't be shortcut by paying someone a very few dollars for a very short amount of training. I doubt if any of us were that smart - maybe you are. You insult our profession by insisting that all that you need is far less than what we needed. And nobody wants to tutor someone who has already shown they are not willing to listen.

Slow down, quit blaming everyone else including the people on this forum, and take the time to start the learning process. Pay your dues. This may mean you won't pass the class this semester. If you work really hard you will eventually get there. We did.

As i stated to you earlier,
please post your understanding of your assignment. We understand that you want a tutor, this site is wonderful for tutoring, just ask for help. many of us work full time jobs. we will answer all your questions.
james

We know you're frustrated, but stay calm....R.E.L.A.X. You don't need a tutor like you think you do. You're making this stuff harder than what it is. Trust me, this stuff is not hard.

So, go grab your favorite adult beverage (a good craft beer works for me), sit down at your computer, and watch those videos that DrBitBoy linked. Keep a copy of the RSLogix5000 instruction set nearby as well, which was also linked, so that you can refer to it. As was suggested - if after or during the time you've watched the video/s, you are still hung up somewhere, come back here and inquire. It appears since you're not working and just have night school in the evenings, you should have plenty of time during the morning and afternoon hours to get up to speed.

Like I said before in my previous post and someone else iterated as well - you have to commit the time and the effort. There's no short cuts. If you show us here that you're putting in the time and effort (watching the videos on your own, etc...) and you're listening, then there are a lot of good folks here that will help you.

For any given homework assignment or task at work, you must consider these instructions as the customers specifications.
1. read the specifications several times.
2. write down your understanding of what you read in a step by step fashion.
3. review what you wrote down and see if it makes since, modify if necessary.
4. Get with the mechanical designer and discuss the project openly and honestly. When your opinions differ in regards to an operation, discuss it, don't ignore it. there must be a reason for a difference of opinion. modify your instructions and i/o to accommodate the mechanical design if possible. Mechanical design may have to be changed due to plc programming limitations.
YOU BOTH MUST be in agreement on all points of operation before going to step 5. you may have to modify/rewrite step 2 and 3 based on the discussion.
5. step through your notes again this time, you are the one following the instructions. In other words, you are the plc. Write down on paper the events you are doing.
For example, turn on hydraulic motor 1, write down hydraulic motor 1 on. If a sensor is needed, write that down.
6. continue through the instructions. When you turn off the motor, mark a line thru it.
7. go through your instructions with all the sensors, motor aux. contacts, outputs documented. Modify if necessary.
8. repeat step 6 until no changes are made.
9. Try to group your data words into some organized fashion. The more programs you write, the more organized you become
10. write the plc program using your notes in a step by step manner.
10A Over half way through writing the program you WILL realize a different/better way of doing something you are almost done writing
(or a new spec will require it) and you will completely rewrite it
10B It WILL happen more than once.
Note: 10A and 10B added to list. thanks Aabeck, member plctalk.net forum
11. DOCUMENT EVERYTHING!!! You may remember things today, but in 5 years and hundreds of programs later, you won't
remember, especially at 2 am, so DOCUMENT EVERYTHING. use easy to understand tags and rung comments.
12. MAINTENANCE is your best friend and your worst enemy.
if you work with them and find out what they can do, write the program where they can trouble shoot the program. they will be able to fix the problem and everyone will be happy.
BUT
if you write the program to where you are the only one who understands what is going on, maintenance can't fix the issue, the machine is down, production is down,
management hears about it, your boss hears about it, then you hear about it - rewrite the program or else. you get calls all hours of the day and night.
this still holds true, a machine can cost a billion dollars, but it's not worth 10 cents if maintenance cannot trouble shoot the issue and fix the issue.
everyone has their own style of programming and you must develop your own way as well.
13. when the customer is in your shop and brings maintenance, discuss things with them, let them see your code, be open.
if they make suggestions, write them down, don't ignore them. their ideas may save you days of programming.
14. install the program and leave in program mode if possible so you can to debug your i/o
15. when writing your instruction manual(s), use your notes from step 9. Use easy to understand English language. specify the i/o, timers, counters, outputs when possible.
this will help maintenance even more to see what is going on.
16. Question for you, when is a machine and plc the most dangerous and why?
When it’s first powered on – when power is first applied to a machine, you don’t know how things are wired.
When you energize the plc outputs, you don’t know how they are wired.
When the plc is put into run mode the first time, it will do what you told it to do, NOT what you wanted it to do.


17. debug the program.
Remember, the program will always do what you told it to do, NOT what you wanted it to do.
18. IF you can ask a what if this happens type of question, YOU MUST have an answer, EVEN IF its a 1 in a million chance. that what if situation will happen in the first 30 minutes of production runoff in front of the customer.

regards,
james

You're lucky you even get a class. I got my job knowing nothing about PLCs. I was thankfully thrown on some easy projects and have patient co-workers that explained the ins and outs of PLC programming.

People have tried to help you for 2 days now. You don't NEED a personal tutor. This site is full of experts willing to help but you have to show a willingness to listen to them. Several have asked you to post a better image of the ladder logic, what is your understanding, where are you stuck. And you haven't once answered any of those questions. Nobody here is going to do the work for you and most are full timers themselves. Put in some effort to ask the right questions and people will help you.

jessedurr said:

You seem like you know what you’re talking about. Could tutor me for 40 an hour?

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Man I have been trying to hire him for 125 an hour and your offering 40?

Time for the OP to put up or shut up. Here's what I would be telling you if you had hired me to be your tutor.

Look up the descriptions of the FLL , MOV, and COP instructions and tell me what you think Rung 1 does.
Write the values of all the elements of the A and B arrays following the execution of Rung 1.

Look up the descriptions of the TON instructions and draw a timing chart for the .EN, .TT, and .DN bits for both Timer1 and Timer2.

Based on that, tell me the True/False state of Answer1 through Answer15 when the program has been running for five seconds.

Do all of the above before you try to run the logic on a simulator. Post your answers here. If any of the members here disagree with your conclusions, I'm sure they'll tell you. Be prepared to defend your answers and be willing to listen and learn which of your underlying assumptions are mistaken.

Steve Bailey said:

Look up the descriptions of the FLL , MOV, and COP instructions and tell me what you think Rung 1 does.
Write the values of all the elements of the A and B arrays following the execution of Rung 1.

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I think you meant 'Rung 0'