Going to take a stab at this. The top adjustment is the time range, now it seems to be set at 6 to 60 timeing range. The next knob is the fine adjustment, set it at 5 and you will be in the middle of the range you selected with the top button. Its labled "TON" thats Time On Delay I think, its going to start someting after you start a roast, maybe the time after the roast begins till when the fan comes on. The next two knobs adjust the delay before this is turned off, "TO OFF". Maybe this is a post roast cool down function. To find out what it controls set the time short on the TON and longer on the TO off and see what comes on.
Ringo