I never worked with this exact piece of gear, but I did babysit one exactly like it years ago.
Yes, the thumbwheels programmed this monster. Each audio source had a number, dialing those numbers on the thumbwheels told the "brain" what to fire next. An analog clock kept time of day, and when the top of the hour was coming up, it would arm the "brain" to finish the event it was playing then jump to the beginning (event 1 on the first thumbwheel row) to start a new hour. All station-recorded carts had to contain cue tones to fire the sucker, and your music tapes (supplied by a syndicated format) also contained tones, usually at the very end of a song fade, making for some incredibly loose segues.
If an audio source was not ready (cart not loaded, tape not threaded) it would not skip to the next event, but rather it would just sit there staring at you while a sonoalert screamed in your ear. That was really fun, as I was doing a live show on an AM Top 40, with very short songs, and having to mind this thing for our easy listening FM. Plus, the AM control room was in the very front of the building and the FM automation was in the very rear, next to the transmitters. That assured you got your road work in during your shift.
Note the rather large relays on the front panel. Whenever they triggered, you knew about it, as they sounded like a truck shifting gears.
What's really funny is this thing was state-of-the-art at that time, and we actually bragged about having one.
