Alrighty, I traced the area scanner to its termination. Looks like the cable is split out. Some wires, including the OSSD1 and OSSD2 land on a Minotuar MSR127TP safety monitoring relay. The other wires seem to land on the "SHIELD" termination on the DIN rail. Now here's the funny part. I traced all this out, took pictures, buttoned up the controller, powered up and then went to run the program again to capture any codes, and the darn thing started working as I backed away 5 feet. It is just sitting there happily moving blocks around the board. The safety interrupt is working correctly, and the green light is illuminated until you breech the 5' safety zone at which time the red light turns on and the robot stops movement. I wish I knew what I did, but it "seems" to be working for now. I plan on switching up programs and seeing if those will run in AUTO as well.
I deeply appreciate everyone on this thread and your willingness to help out a frustrated teacher. Teaching on this cart is just so different than a real world cell.