Nonwoven machines are powered by electric motors. Many of the motors on these machines can be sped up or slowed as needed. This is done using variable speed motor controllers. Variable speed motor controllers are electronic devices, often called “drives”, that can change the speed of a motor either manually, when an operator turns a potentiometer, or automatically as when a motor changes speed in response to a change in tension. Normally machine operators do not adjust the controllers themselves as they are shut up in control cabinets. The most common type of controller used is an AC inverter driving an AC motor. However, there are still many DC motors and controllers in service. In a large nonwoven line, there can be 30 or more motor drives that communicate with each other over networks. This communication enables the drives to keep all sections of a nonwoven line operating at the correct speed.