This read-write object selects whether the LNB's local oscillator mix is low-side(0) or high-side(1). This determines whether the terminal (downlink) frequency equals the LO frequency minus the IF frequency (low-side mix) or the LO frequency plus the IF frequency (high-side mix), directly changing the arithmetic used to compute the terminal frequency -- getting this wrong produces a terminal frequency calculation that's off by twice the IF frequency. For a standard Ku-band LNB where the downlink frequency is below the LO frequency, an admin would set this to lowSideMix(0) so the unit correctly subtracts the IF frequency from the LO to arrive at the true terminal frequency.