An encoder is a device that compiles or converts a signal or data into a signal that can be used for communication, transmission, and storage. The encoder converts an angular displacement or a linear displacement into an electrical signal, the former being called a code wheel and the latter being called a code ruler. According to the readout mode, the encoder can be divided into contact type and non-contact type; according to the working principle, the encoder can be divided into two types: incremental type and absolute type. Model: EN11, HSM1AF15