BNC 645 - Manual (Page 126)

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automatically limited to 4k points. Extra points are removed using decimation.
AM:INTernal
:FREQuency{<frequency>|MINimum|MAXimum}
Specify the frequency of the modulating waveform. This applies only when the
modulating source is internal. The range is from 2 mHz to 20 kHz and the default
is 100 Hz.
AM:INTernal
:FREQuency? [MINimum|MAXimum]
Query the internal modulating frequency. The frequency (in hertz) of the
internal modulating waveform is returned.
AM:DEPth {<depth in percent>|MINimum|MAXimum}
Specify the internal modulation depth (or “percent modulation”) in percent. The
range is from 0% to 120% and the default is 100%.
Notes:
• When an external source is selected, the modulation depth is controlled
by the ±5v external signal applied at the Modulation In connector on the
rear panel. Specifically, the output will be at the maximum amplitude
when the modulating signal is at +5v, and the output will be at the
minimum amplitude when the modulating signal is at -5v.
• The modulation output of Model 645 will not exceed ±5V peak (into a
50Ω load) even if the modulation depth is greater than 100%.
AM:DEPth? [MINimum|MAXimum]
Query the modulation depth in amplitude modulation. The modulation depth (in
percent) is returned.
AM:SOURce {INTernal|EXTernal}
Specify the modulating signal source. If an External source is chosen, the carrier
waveform is modulated with an external waveform. The modulation depth is
controlled by the ±5v external signal applied at the Modulation In connector on
the rear panel. Specifically, the output will be at the maximum amplitude when
the modulating signal is at +5v, and the output will be at the minimum
amplitude when the modulating signal is at-5v.
AM:SOURce?
Query the modulating source in amplitude modulation. “INT” or “EXT” string
indicating the modulating source will be returned.