Place them facting the conveyor you want them to take items from, set the item type. The robot arms will then proceed to pick up the item without slowing down the conveyor and place it on a conveyor behind them. They can't place items on the ground or directly into hoppers.
Robotic sorters will work outside Rooms, but get a significant speed penalty, although this version isn't as slow as the basic version.
Intermediate Robotic Sorters can be upgraded into Upgraded Robotic Sorters.