An absolute encoder has each position of the revolution uniquely numbered. This means that instead of an output of pulses, you get an output that is a specific value in a binary format. This is very useful when exact positioning is a must. Since each location in an absolute encoder's revolution is a unique binary value, if the power should be lost, the actual value of the position will be known when power is restored. The exact position will be known even if the controller loses power and the process is moved.