Looking for some examples of going from relays to PLCs

Yes yes another student question.

I'm doing some research and I'm looking for some detailed examples of relay logic diagrams and hardware wiring and how to convert to ladder logic and PLC wiring. I've having trouble just finding old relay logic examples on the net.

In so many book it is said how PLCs replace relay logic and ladder logic looks like relay logic. I'd like to see it to believe it.

I have found this site which is a pretty good example. But I'm having trouble with comming up with more.

Does anyone have any sites they can point me too? Or maybe some good keys words to google with?

try these: http://www.ibiblio.org/obp/electricCircuits/Digital/DIGI_6.html
http://www.patchn.com/
http://www.thelearningpit.com/

Find yourself an older bldg built before 85 or so and NOT upgraded.

IF you can get in look at the elevtor controls. Should be all relay.
Same for fire alarm.

Same for REAL OLD telephone switch stations.

Go to an elevator outfit and ask to look at old prints. Same for the college you go to - ask the guys in Facilities.

Automotive -- starter motor is still started with a relay, turn signals are done with a relay (flasher).

JWise,
Here is a typical schematic using relays: