help please

[coxy]

hi guys im new here, and dont really have a great knowledge of plcs. i am currently studying for an onc in engineering and one of my subjects is plcs. this is obviously on a very base level but i have an assignment due with the following question, which i require some help and looks like all of you are experts here goes 1) Describe in some detail the following types of controller and suggest typical industrial uses. Say why each is suitable to your chosen task. a. PLC single chip computer b. Mitsubishi Fx PLC c. Mitsubishi Alpha Block. i have searched the web but i just get pages and pages, so if you could point me in the direction of some good websites or help me out by trying to answer them. wanting approx 400 words on each which seems daunting when you dont know much at all! anyway thanks for any help guys coxy

[mlarkinp]

http://www.meau.com/eprise/main/Home/home This site should help. Locate who reps Mitsubishi in your area and see if you can get some information from them.

[coxy]

anyone elsehelp on this matter, still cant find enough and its a matter of urgency now :(

[kevinprior]

for your mitsi alpha, try this page http://www.electrodepot.com/al24mrd.htm it has a little description and also some links to application examples together with some pics. For your single chip PLC try this article http://www.autofieldguide.com/articles/080408.html Hopes this helps

[gravitar]

I'm not too familiar with the Mitsu line but I recognise the fx series as being their small controller line, and I'm then guessing the Alpha is something on par with the SLC-500 or controllogix product line. When I was in engineering school, PLCs were discussed VERY little, if at all. Much more emphasis was placed on build-it-yourself solutions, like the single chip controller in your question. There are legitimate used for both, though. When I think of applications for microcontrollers, I think of single or small quantity runs of "hobbyist" projects or VERY LOW BUDGET commercial applications. On the other hand, it would be appropriate to build a circuit around a microcontroller when the production run is expected to be high. Controllers for automotive applications, furnaces, test equipment, medical/lab instruments, thermostats, etc. are examples that come to mind. So you have both ends of the spectrum covered by the single-chip computer. In the middle are PLCs.. Anything that is a one-off or low production quantity, and yet generates high $$ would be a good home for a PLC. You see this EVERYWHERE in manufacturing. A machine is built for one particular purpose, and there isn't another one like it in the world. But, that manufacturing process could generate millions of dollars a year. The owner of this machine won't tolerate "bugs" and downtime, but they don't want to wait years and spend millions on R&D either. The PLC fills this niche. In recent years, as the cost of PLCs have gone down, we start to see them even in machines that are mass produced. A PLC is a strong sales incentive over a custom circuit board to the industrial customer, because their maintenance staff are already trained on how to operate and troubleshoot them. So anyway.. that's my $0.02 worth.. hopefully that will give you some ideas you can learn more about and expand upon for your paper..