RIGOL    Chapter 5 Modulated Waveform Output 
  DG4000 User's Guide 
To Set the Modulating Waveform Frequency 
 
When internal modulation source is selected, press FM_Freq to set the 
modulating waveform frequency. 
  Input the desired frequency value using the numeric keyboard or direction 
keys and knob. 
  The modulating waveform frequency ranges from 2mHz to 50kHz, and the 
default value is 100Hz. 
Note: This menu will be grayed out and disabled when external modulation source 
is selected. 
 
To Set the Frequency Deviation 
 
Frequency deviation is the deviation of the modulating waveform frequency 
relative to the carrier frequency. Press Deviation to set the FM frequency 
deviation. 
  Frequency deviation must be lower than or equal to the carrier frequency.  
  The sum of frequency deviation and carrier frequency must be lower than or 
equal to the sum of the current carrier frequency upper limit and 1kHz. 
 
When "Ext" modulation source is selected, frequency deviation is controlled by the 
±2.5V signal level at the [Mod/FSK/Trig] connector at the rear panel. Positive 
signal level corresponds to frequency increase and negative signal level 
corresponds to frequency decrease. The lower the level, the less offset is 
generated. For example, if the frequency deviation is set to 1kHz, +2.5V signal 
level corresponds to a 1kHz increase of frequency and -2.5V signal level 
corresponds to a 1kHz decrease of frequency.