GW Instek AFG-2225 User Manual - Manual (Page 83)

MODULATION
83
Note If an external modulating source is selected, the
frequency deviation is limited to the ± 5V MOD
INPUT terminal on the rear panel. The frequency
deviation is proportional to the signal level of the
modulation in voltage. For example, if the
modulation in voltage is +5V, then the frequency
deviation would be equal to the set frequency
deviation. Lower signal levels reduce the
frequency deviation while negative voltage levels
produce frequency deviations with frequencies
below the carrier waveform.