Select the output function. The selected waveform is output using the
previously selected frequency, amplitude, and offset voltage settings. The
FUNC[1|2]? query returns “SIN”, “SQU”, “RAMP”, “PULS”,
“NOIS”, “DC”, or “USER” (without “”)
If you select “USER”, the instrument outputs the arbitrary waveform
currently selected by the FUNC[1|2]:USER command.