This attribute allows the user to request an equivalent noise bandwidth for the resolution bandwidth filter used in the spectrum analysis. This corresponds to the spectral width of the window function used when performing a discrete Fourier transform for the analysis. The window function which corresponds to a value written to this object may be obtained by reading the value of the WindowFunction attribute. If an unsupported value is requested, the device may return an error, or choose the closest valid value to the one which is requested. If the closest value is chosen, then a subsequent read of this attribute will return the actual value which is in use.