Probably the same set-up as the 2310, and it took me a while to figure it out, too....
It sounds like you're talking about the floor-mounted control(s), yes? There are two:
1) on the 2310, the faucet-like knob that protrudes horizontally (sort of beneath the seat) controls the drop speed, of both the mid-mount mower deck and the 3-point hitch arms. (Both of these systems are connected.) The hydraulic pump only does the lifting, whereas the drop is simply by gravity. The knob can also be used to hold this system in the up position by closing it (clockwise) all the way once the system's lifted to its highest position. This is useful for preventing the slow downward creeping, especially after engine shut-off, that is normal, of either the MMM or, I believe, a 3PH implement. (I don't have any 3PH "stuff" yet...) The drop speed control is there, I believe, because sometimes you want "quick," sometimes "gentle." I'm betting that becomes an issue with 3PH implements, which can be pretty heavy. Maybe someday I'll find out.
2) The knob that protrudes more or less vertically from the floor is a "lowest-point stop" that's used for setting the working height of the mower deck. It's toally mechanical, and does just that: moves a stop-nut along a threaded shaft that will bear on the MMM linkage when the MMM is dropped, preventing further downward movement.
Hope this helps!
