Clearly the question assumes you have seen examples of PLC applications in your studies. Applications like Traffic Light or some manufacturing process like machines you see on "How It's Made".

Actually to completely answer the question, you need to consider the interfacing of the input and output terminals to your machine. Many PLC applications operate on a 24VDC control bus while others operate on 120VAC for their most common I/O. There are generally both sets of I/O modules available for any PLC except for some dedicated micro PLC's.

Generally we don't help with homework here. But in this case, question #4 seems to be a little out of character with the first three. So, what kind of PLC applications have you seen lately?

hi ....

I have seen:

Your information on Siemens is all wrong. Go back and read the specs more carefully. In addition, some of the models you picked out are obsolete.

ok give some hints, links if you may

Hi night wolf,

You might find some interesting PLC information here for your task;

www.entertron.com

Cheers, AussieBob

thanks bro

well regarding applications I think the most important parameter to take into account is the kind of I/O you need for the aplication you chose.Compare those with the I/O you have for each model and memory speed. For example i have seen PLC just taking analogic data to calculate the power spent on a high power turbine (actually it transforms internally the analogic signal into a digital). In this case you need an analogic input to do this. Check the C7-635 data, it could be ok.

In the case of the digital I/O those are mostly used to receive and to send just single signals. It means they can be used to control processes like tanks filling, etc. Certainly almost there are not any production process without PLCs involved.

everybody if you may look at my answer to all Q? and tell your final ideas about it and could some one provide me with links and thoughts

thank you all

I see it has been almost two weeks of no activity. If you still need a little fodder...

http://www.thelearningpit.com/

Application suggestions? How about:

Elevator control. Note that all building codes (that I know of) do NOT allow a PLC to control passenger cabs, but material only elevators can be.

Doors, especially effective for man-trap, bio-hazard wash areas, particulate contaminate wsh down areas. I am (oddly enough) in the door business, and use micro and baby PLCs often.

Hope this is of some use... as well as not too late.

thank u very much brother... ^^ it is late for the homework but it's not that late for my self knowledge

I looked at it and it is helpful ^^

thank you very much