Defense Turrets can spawn in rooms upon boarding a derelict and will always start in a powered down state.

Defence turrets are never present in a room with an interface terminal.

They must be activated and deactivated through an interface terminal and will instantly destroy any drones or enemies that enter or are present in the room with them if active.

Defense turrets still require power in the room, without which the turret will not fire even if armed. [1]