Encoder Filter Frequency

Setting the maximum allowable count frequency for an encoder is useful for reducing the effect of noise on the encoder lines. Noise on the encoder lines can be interpreted as extra encoder counts. By setting the frequency to the lowest possible setting required for the motion application, you can ensure the highest degree of accuracy in positioning. In choosing the appropriate value, you must take into account the counts per revolution of the encoder and the maximum velocity for the axis in question.

For example, with a 20,000 counts per revolution encoder and a maximum velocity of 3,000 RPM (50 revolutions per second), the encoder signal could be as high as 1,000,000 counts per second. A maximum count frequency of 1.6 MHz would be appropriate in this case.

Tip  When the encoder filter is changed, reset the position to prevent an erroneous count.