User manual

3390-900-01 Rev. C / January 2009 Return to Section Topics 5-9
Model 3390 Arbitrary Waveform Generator User’s Manual Section 5: Waveform Output Operations
To generate an arbitrary waveform from a remote interface:
FUNCtion USER {EXP_RISE | EXP_FALL | NEG_RAMP | SINC | CARDIAC}
DATA:DAC VOLATILE, {<binary block>|<value>, <value>, …}
DATA VOLATILE, <value>, <value>, …
FORMat:BORDer {NORMal|SWAPped}
DATA:COPY <destination arb name> [,VOLATILE]
Amplitude modulation
Amplitude modulation allows the amplitude of the carrier waveform to vary with the modulating
waveform. Only one type of modulation can be active at one time; if amplitude modulation is
enabled, the previously selected modulation is automatically disabled. In addition, when amplitude
modulation is enabled, sweep mode and burst mode are disabled.
Carrier waveform
The default carrier waveform is sine. You can also choose square, ramp, and arbitrary waveforms.
The default carrier frequency is 1 kHz for all waveforms. Each carrier waveform has its own
acceptable range of frequencies. Refer to Table 4-1, Waveform function frequency ranges for
details.
Modulating waveform
The Model 3390 accepts either an internal or external modulating source.
The default source is internal with a default frequency of 100 Hz (the acceptable range is 2 mHz to
20 kHz). The default internal modulating waveform is a sine waveform, but you can also select any
of the following:
• Square waveform with 50% duty cycle
• URamp (up or positive ramp with 100% symmetry)
• DRamp (down or negative ramp with 0% symmetry)
• Triangle waveform (ramp with 50% symmetry)
• Noise waveform
• Arbitrary waveform (limited to 4 K points with automatic decimation)
Select the external modulating source to modulate the carrier waveform with an external signal
present at the Modulation In connector on the rear panel.
Modulation depth
The modulation depth controls the magnitude of the amplitude variation of the modulation output.
It is defined in the following formula:
Modulation Depth = (Max Amplitude - Min Amplitude) / Amplitude x 100%
Where: Amplitude is the specified amplitude of the carrier waveform; Max Amplitude and Min
Amplitude are the maximum and minimum amplitudes of the resulting modulation waveform.
When Modulation Depth is 0%, the amplitude of the modulation waveform stays at half of the
specified amplitude of the carrier waveform. As a result, Min Amplitude may be negative when
Modulation Depth is larger than 100%. The default Modulation Depth is 100% and the allowable
range is from 0% to 120%.
Choosing the external source means the modulation is controlled by the specified modulation
depth and the ±5 V signal levels of the external waveform. When the external waveform is at +5 V,