Step motors have several advantages over other types of motors. One of the most impressive is their ability to position very accurately. Standard step motors have an accuracy of +/-5%. The error does not accumulate from step to step. This means that a standard unit can take a single step and travel 1.8° +/-0.09°. Then it can take one million steps and travel 1,800,000° +/-0.09°. This characteristic gives it almost perfect repeatability. Repeatability is the ability to return to a previously held position. It can achieve the same target position, revolution after revolution. A step motor will rotate a distance and at a rate that is proportional to the number and frequency of its pulse commands.