EPS is a control dancer and used for closed-loop tension control on winding of endless material. It is a considered and "active" dancer control system. EPS is operated as an electrically controlled P/F actuator providing a large range of adjustment for the user-set desired tension level

The position of the dancer is measured by means of a rotary encoder, giving a standard output signal specially-designed to be able to maintain precise tension control even under high-dynamic speed variations

Functionality using the example of a typical unwinding process: 
At the unwinder a motor-driven chuck supports the material roll. The following process needs material feeding with process-specific dynamic and well-defined tension. 

EPS serves as link between unwinder and process.

Material accumulator
Additionally EPS functions as an accumulator. It can dispense or receive the material depending on the dancer position.