Which component is responsible for comparing the ordered and actual rudder angle indicators?

The component that compares the ordered and actual rudder angle indicators is the turn helm wheel. This device is directly involved in steering the vessel and provides the physical input necessary to indicate the desired rudder position. When a helmsman turns the helm wheel, it sends signals to the rudder control system, which adjusts the rudder angle accordingly. The system then compares the ordered angle (the angle the helmsman wishes to achieve) against the actual angle of the rudder to ensure that the steering commands are executed accurately.

The other components listed do not serve this specific function. The anchor windlass is used for raising and lowering the anchor, while the conveyor load/unload device is used in materials handling, and the wildcat clutch lever is related to the operation of an anchor windlass mechanism. None of these components is involved in the rudder angle control or comparison process in steering a vessel.