An encoder can be either incremental or absolute.
An incremental encoder usually generates a series of pulses in response to a linear or rotary motion. These pulses can be used to measure speed or be fed to a PLC or counter to keep track of a relative position. The output signal of an incremental encoder is normally an electrical square wave signal with a certain frequency related to the speed of the encoder shaft.
Absolute rotary encoders generate a position value that indicates the actual position of the encoder shaft directly. A major benefit of absolute encoders is that if the application loses power, the encoder is able to keep track of its position also if the shaft is turned during the power loss. This is due to the genuine absolute scanning principle. An absolute encoder can also be used to calculate a digital speed value. By internally dividing the difference in position with a small delta time an accurate speed value can be calculated and transmitted to the subsequent electronics.
Other types of encoders such as tachometers, i.e. an encoder with analog current outputs (0-20 mA or 4-20 mA) related to the speed or position of its shaft, may also be offered from Leine Linde. Thus the principle function of the encoder is always the same: an encoder converts a mechanical movement of its shaft into an electrical measurable unit representing the shaft’s speed or position.
Encoders are often used on electrical motors in the paper and steel industries, cranes and material handling systems as well as various types of measurement, testing and inspection systems.