Invert the waveform relative to the offset voltage. In the normal mode
(default), the waveform goes positive during the first part of the cycle. In the
inverted mode, the waveform goes negative during the first part of the cycle.
The :OUP[1|2]:POL? query returns “NORM” or “INV”. The waveform
is inverted relative to the offset voltage. Any offset voltage present will
remain unchanged when the waveform is inverted.