Interfacing PICs and PLCs

I'm currently a student enrolled in a technology program at a university and I was wondering if you guys had any ideas for an application that interfaced a PIC (Basic Stamp II) to a PLC (Micrologix 1200) using a convertor board that took the PICs PWM output and converted it to an analog value. I would take this converted value and connect it to a Analog module attached to the PLC. I'm thinking that "cascading sensor technology" would be a good title for the endevour but I can't seem to generate any feasible "real world" applications. Any info would be appreciated and thanks for your time

Ideal

What about making a traffic light program, plenty of info on that topic .

I have worked a bit with the basic stamps, what about some type of project thats takes an infrared reading into the basic stamp and then sends the data to the processor. This could be used for some type of light curtain or maybe a distance detector.

That doesn't sound like a bad idea although i'm limited by the analog module of the PLC it only has 2 inputs and 2 outputs but I could do PWM of certain values from 1 to 2 ms (i.e 1200 ms pulse = 1.2 VDC) in length which would give the exact Analog output value. Based on that I then have 125 possible output values from the PIC to the PLC. More percise analog control than I thought possible and I could make more decisions based on the range (if 1.2 VDC do this if 1.4 VDC do that) with the ladder logic of the PLC. Interesting I might have to research this some more