Basic PLC Info needed. Please help!

May seem like trivial stuff to the proffesionals but i have an assignment due and im really stuck.
The questions are:

1. What is a stand-alone PLC
2. What is a modular PLC
3. What are different programming techniques
4. What are and describe the different types of communication links and networks used in modern PLC systems.

If you could help me with any of these questions i would be exremely gratefull.

Click on the learn plc's at the top of the page, follow that through, perhaps buy Phil's book.
also take a look at: http://www.freestudy.co.uk/
and www.thelearningpit.com

You'd be best off not believing any answers we give you to those questions.

If you need help with homework, that's ok. But, show us what you DO know, first. What do you think the answers are to these questions?

1. Do you think a stand-alone PLC needs a lot of help from the outside world?

2. Is modular likely to mean the PLC comes as a moulded piece of plastic and you're stuck with what you get?

3. On the weekends, I might program in my underwear while highly caffinated. Is that your definition of "style?" Certainly, it doesn't meet the definition of "proffesional." Or, does it?

4. How many examples do you want? There are hundreds or thousands of ways to make PLCs communicate. Hardwiring is just one. I'd like to see a PLC that used Semaphore for communication.

AK

1. No i believe a stand alone PLC acts on is own, it is a single unit possibly only interacting with the machine being controlled.

2. Modular is likely to mean that it comes as it is. With a speific purpose and no scope for change. If you need it to do a different function you have to get a seperate module for that purpose to add to the exsiting one.

3. I dont understand the purpose of this question. However to me if your programming in he privacy of your own home in you underwear i would say it could be considered to be professional. However if you did this at your place of work the answer i would be concerned.

4. I need just a few very basic methods and what they are. I have looked on the net for answers to all of these questions and there are so many possibilties and answers to all of them it is making it difficult to pick out the useful info with going into detail out of my depth.

I have looked on the net for answers to all of these questions and there are so many possibilties and answers to all of them it is making it difficult to pick out the useful info with going into detail out of my depth.

Click to expand...

just as a general observation ... on an assignment like this, why not put down ALL of the information that you can find on the web (it’s just cut-and-paste) and then point out the differences and the similarities of the various viewpoints? ...

look at it this way ... an instructor who would make this type of assignment is probably not overly concerned with the precise accuracy of your observations ... more likely he is only interested in the fact that you made a serious effort to do the necessary research ... indeed, the very fact that there are so many conflicting viewpoints involved in the material that you’ve found so far might be well worth documenting ...

example:

on page 123, book ABC says: “blah-blah-blah” ... on the other hand,
on page 321, book XYZ says: “yada-yada-yada” ... this indicates that different manufacturers use different terminology to represent similar concepts ... etc., etc.,

stuff like this might not win you the Pulitzer Prize ... but it might be all (or even exactly) what you need to get the assignment completed with a passing (or even an excellent) grade ... the basic ideas: (a) did you take the assignment seriously? ... (b) did you make an honest effort to do the research? ... (c) does the material which you are submitting reflect the amount of work that you put into completing the project? ...

disclaimer: this is just something to think about ... consider your instructor’s personality and reputation before you embark on this particular course of action ... my personal experience is that the best instructors tend to reward EFFORT ... especially with assignments which involve subjective answers ... such as the one which you’re apparently working on ...

good luck ... and welcome to the forum ...

jma173 said:

3. I dont understand the purpose of this question. However to me if your programming in he privacy of your own home in you underwear i would say it could be considered to be professional. However if you did this at your place of work the answer i would be concerned.

Click to expand...

Actually I would be more concerned if he was programming at work while not wearing his underwear!

3. I dont understand the purpose of this question. However to me if your programming in he privacy of your own home in you underwear i would say it could be considered to be professional. However if you did this at your place of work the answer i would be concerned.

Click to expand...

That question pertains to different languages used for programming plus saving reusable code.
LMAO That means laffing my A off for those that dont know.

GOOD answers jma...some of the best responses I have seen from a student even with it being wrong and bad writing.

http://www.freestudy.co.uk has the Edexcel information pertaining to the HNC program.

I remember when I asked that foolish question:

Should there be a separate posting section for students"?

Now, my question, for what purpose should a unitary plc be programmed in your underwear if it is thursday, and the plcs.net server is down?

If not sure, call 1-800-FAT-CHANCE which is actually Sara Lee, on second thought, DO NOT call them.

regards.....casey

Well, JMA, you came back with an answer that shows thought. I commend you for this, since many students don't bother.

Try this http://www.freestudy.co.uk/plc/

You are incorrect on "modular". This means that hte PLC and its power supplies and I/O modules come in separte modules that can be connected to meet project requirements.

I'm a little confused by question 3, but I've only been dong this for twenty years.

I suppose the last question makes sense to a beaurocrat, but it can have a lot of different meanings. I guess I would go for "serial, ethernet, and wireless" as at least a reasonable answer.

Keep thinking, and keep coming back.

Tom Jenkins said:

I'm a little confused by question 3, but I've only been dong this for twenty years.

Click to expand...

I tend to think that the question will relate to 'language', i.e LAD, FBD, STL, SCL, CSF, rather than, 'sitting at a desk', 'Smoking a cigarette while typeing' etc

That is the only explanation that I can think of.

Paul

find basic information regarding PLCs and SCADA

hi,

you can visit

techie-help.com u gonna find some basic concepts and stuff about PLCs and SCADA.

Pratik8950,

Jay flunked out of the course 10 years ago and has not been seen or heard from since then.

ohhhh

havent seen the date he posted , thnx for mentioned it