The Fill Filter With Constant dialog lets you fill the Inphase, Quadrature, or Complex filter with a constant (obviously!) A filter which has all coefficients set to a constant is sometimes called a " comb filter" , a " boxcar filter" , or a " moving average" .

You specify the number of filter taps and the constant fill value. You can enter the constant explicitly, or, if the " 1/NTaps" box is checked, ScopeFIR will automatically set the fill constant to be the reciprocal of the number of taps. This results in a filter with unity gain at DC