Drone cannot grab items from chest

[Barbaric 0]

My drone has the inventory controller upgrade and when it goes to grab items from a chest,

it simply just floats over it. How can I get it to get the items from the chest?

Piece of the code it uses to grab items from the chest:

        for ii = 1, invcon.getInventorySize(0) do

            invcon.suckFromSlot(0, ii, 64)

        end