The mounting ring can be rotated on the stationary shaft to the position at which a reference signal should be generated. Then the mounting ring secures by screws in fixing clamps or a tensioning ring. Built-in rotary encoders have no need for an additional adapter flange. Moreover, it is significantly simpler to adjust the position of the reference signal output than for encoders with separate couplings. This reduces mounting time.
Some versions also generate commutation signals for use with dc brushless motors.
Rotary encoders are designed specifically for dc brushless motors can provide both incremental and absolute data. An example is the ERN 1387, which is employed with specially developed electronics for interpolation and other signal processing. Digital interpolation can boost the frequency of encoder outputs to increase the effective resolution of the system. For example, applying the 4,096 fold interpolation to a 5,000 line encoder signal produces about a 2-million count signal for processing by down stream electronics. These values are then encoded into 25-bit words that are clocked serially to signal processing electronics.