Wherever and whenever possible, the world is transitioning from analog to digital, and in machine tools, we are seeing the move toward digital axes in drive technology. The Heidenhain Corporation (www.heidenhain.com) EnDat 2.2 new digital bidirectional interface for encoders is another example of this trend toward digital. The EnDat 2.2 is an improved serial interface for quick-response drives capable of outputting absolute position values as well as requesting or updating information stored in an encoder. The interface offers purely digital transmission over four lines. The analog signal can no longer be disturbed by interference on the way to subsequent electronics because it is already interpolated in the encoder. Heidenhain says this improves drive characteristics with regard to positioning accuracy, repeatability, speed stability and dynamic response.
Since the encoder takes over all interpolation, the subsequent electronics can be simpler and therefore smaller. Due to improved encoder electronics, there is no longer a need for a remote sensing power supply. The reduction in the number of data lines results in smaller connectors and simplifies cabling, and both of these effects decrease the required installation space.