Defined Values for modulationWaveform
| IVIFGEN_VAL_AM_INTERNAL_SINE | Sinusoid waveform |
| IVIFGEN_VAL_AM_INTERNAL_SQUARE | Square waveform |
| IVIFGEN_VAL_AM_INTERNAL_TRIANGLE | Triangle waveform |
| IVIFGEN_VAL_AM_INTERNAL_RAMP_UP | Positive ramp waveform |
| IVIFGEN_VAL_AM_INTERNAL_RAMP_DOWN | Negative ramp waveform |