The EnDat interface can transmit position values from incremental and absolute encoders as well as transmitting or updating information stored in the encoder, or saving new information. Digital drive systems and feedback loops with position encoders for measured value acquisition require fast data transfer with high transmission reliability from the encoders. Further data, such as drive-specific parameters, compensation tables, etc must also be made available. For high system reliability, the encoders must be integrated in routines for error detection and have diagnostic capabilities.The EnDat interface from Heidenhain is a digital, bidirectional interface for encoders.It is capable both of transmitting position values from incremental and absolute encoders as well as transmitting or updating information stored in the encoder, or saving new information.Thanks to the serial transmission method only four signal lines are required.The data are transmitted in synchronism with the clock signal from the subsequent electronics.The type of transmission (position values, parameters, diagnostics etc) is selected by mode commands that the subsequent electronics send to the encoder.The EnDat interface provides everything needed to reduce system cost per axis up to 50% - and at the same time improve the technical standard.The most significant benefits are: cost optimisation, improved quality and higher availability.