Or both.
Mechanical limits adjustable under the Motor body are best for preventing damage where excessive travel could lead to the Dish hitting a wall or similar.
Following common or garden control systems safety techniques, you should also set software limits a little tighter than the hardware limits.
Actually you could do it the other way around if you like - we're only talking Satellite Dishes, not Boilers or Chemical Factories!
Not sure about the Dark Motor, but a Moteck's mechanical stops are under a label on the underside of the body and you can only get at them with the Dish de-mounted: This may lead you to a simple conclusion as to what to do ......... !!