ADV200 • Functions description and parameters list 83
17 – ENCODER
The closed-loop control mode requires a speed reading by a digital encoder on the motor shaft. The optional EXP-
ENC card is necessary in order to acquire the encoder signals. Optional cards have been developed to acquire differ-
ent types of encoder signals. These enable the drive to use both incremental and absolute signals as its feedback. The
natural variation in speed generated by machine load induction, known as slippage, can be compensated by the speed
feedback supplied by the encoder in V/f mode. In the eld oriented vector mode, closed-loop encoder feedback is es-
sential for correct drive operation.