423.2.4 X3A EnDatEncoderThe EnDat encoder provides two differential analog channels for incrementalposition and one serial data channel with clock for communication with theencoder. This serial data channel can provide the drive with the absoluteposition of the motor as well as other operating data. The EnDat encodermust be version 2.1 or greater for compatibility reasons.The analog cosine and sine wave signals of tracks A and B have avoltage of 1 Vpp with an Offset of 2.5 V. This analog voltage is measuredand a high resolution position value is determined as a result. This highresolution position value is very important for good speed control of agearless motor.Therefore it is absolutely necessary to ensure these signals are wellshielded! Noise on the analog signals resulting from breaks in theshield or improper shield termination will result in vibration in themotor and poor ride quality.The internal stored ppr value is compared to the adjusted value in LF.27.If the two are not the same the drive will trigger the error E.ENCC. Referto parameter LF.26 for more information.During start-up and then every 30 ms a request is transmitted to theencoder and the absolute position is read out via serial communication.This initial readout of the absolute position provides the drive with thecommutation angle for permanent magnet motors. On the very firstoperation of a permanent magnet motor it is necessary to synchronizethe encoder position to one of the pole pairs of the motor. See parameterLF.77 for more information and section 5.11.1.During normal operation, the difference between the internal absoluteposition of the encoder and the measured position value in the drive iscompared. If the two deviate by more than 2.8 degrees, the drive will triggerthe error, E.ENCC. Refer to parameter LF.26 for more information.ENDAT encoders also provide memory for the user to store a copy ofthe motor data. The drive supports the functionality to read and write themotor data to the encoder. See parameter LF.26 for more information.The clock signal serves as synchronisation for the serial data channel.If there is an excess length of cable (10 feet or less), it is OK to coil it intoa loop in the controller. Maintain a minimum diameter of 1 foot and keepthe cable at least 8 inches away from all high voltage power wires.iInstallation and Connection
