doubts in plc applications

i am a final year engineering student.can somebody help me in deciding about a plc application which will not be very costly and novel too at the same time.

You are more likely to get some help if you show what effort you have already put into the assignment. What ideas are you considering? What are the pluses and minuses of each idea?

The way you worded your post it look like you want someone to do your thinking for you. That impression will not get you many responces. Try another post with more information and evidence of your efforts.

How about a sort.

Use a quadrature encoder and a photo cell to meassure the length of widgets and then sort the widgets according to length. A bin full indicator should come on when the bin is full and a new bin should be automatically allocated for the widgets that would have gone to the full bin. A bin empty button empties the bin. If all the bins are full and no bins are available then the sort stops until a bin is emptied. This is a simplified version of a lumber sorter.

There is always the traffic lights, but that is not very challenging for a senior year engineer. We hire college senoir engineers to lay out simple boards and program micro controllers.

I any case the programming is only half of the problem. Selecting the cards and wiring it up is the other half.

Why don't you try creating a PLC itself using a microcontroller kit with some digital I/Os and some analog I/Os ?

Instead of looking for an application , here you create the product itself . Does this sounds novel to you? Let your teachers run any application on it .. it should work !

I have a 1/32 scale slot car track that is 8'X8'x10' (Triange shaped) and use it at some of the shows on the east coast that is PLC controlled. It uses ASI, an HMI, fiber optics to locate the cars. Thats kinda neat, cause you can run any of the 4 tracks manually or with the computer. I like to travel, if the money's right and the beer is cold, well...... beerchug