BNC 645 - Manual (Page 44)

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FUNCtion {SINusoid|SQUare|RAMp|USER}
FREQuency {<frequency>︱MINimum|MAXimum}
VOLTage {<amplitude>︱MINimum|MAXimum}
VOLTage:OFFSet {<offset>︱MINimum|MAXimum}
AM:INTernal:FUNCtion
{SINusoid|SQUare|RAMp|NRAMp|TRIangle|NOISe|USER}
AM:INTernal:FREQuency {<frequency>︱MINimum|MAXimum}
AM:SOURce {INTernal|EXTernal}
AM:STATe ON
Notes
• Only one type of modulation can be activated at one time. When
amplitude modulation is enabled, the previously selected
modulation is automatically disabled.
• Amplitude modulation cannot be enabled with sweep or burst
mode at the same time. When amplitude modulation is enabled,
sweep or burst mode will be disabled.
4.8 Frequency Modulation
Frequency modulation provides a waveform in which the frequency of
the carrier waveform varies with the modulating waveform.
Carrier Waveform
The default carrier waveform is sine. One may also choose from square,
ramp and arbitrary waveforms but not pulse, noise and dc waveforms.
The default carrier frequency is 1 kHz for all waveforms. Each carrier
waveform has its own acceptable range of frequencies. Refer to the table
in Section 3.4 “To Set Output Frequency/Period” for details.
Modulating Waveform
Model 645 accepts either internal or external modulating source but not
both at the same time. The default source is internal, and the default
internal modulating waveform is sine wave. For internal source, one may
also choose from square with 50% duty cycle, URamp (Up or Positive
ramp with 100% symmetry), DRamp (Down or Negative ramp with 0%