In pre excitation mode 2, you can have any duty cycle between pre exc value and 100% depending on battery and Vset voltage. On some alternators, with high duty cycles, the switching of excitation causes so much noise through the phase that this noise can be interpreted as valid phase signal. Thus, the device can go to regulation. To avoid that, we added the ability to deglitch the phase input only in pre excitation mode 2 to be sure that the signal we have are real phase signals. Depending on the duration of the noise our customer can see during pre excitation mode2, they can set the value of deglitcher. If they don't use pre excitation mode2, this value is "don't care".