ITDetectTone::put_Frequency method (tapi3if.h)
The put_Frequency method sets the frequency of the tone for which the TAPI Server should generate a tone event.
HRESULT put_Frequency( long Index, long lFrequency );
Specifies the index of the tone to set.
Specifies the frequency, in hertz, of the tone. For more information, see the following Remarks section.
This method can return one of these values.
You can set up to three frequencies that make up the components of a tone. If fewer than three frequencies are required, specify a value of zero for the unused frequencies. A tone with all three frequencies set to zero is interpreted as silence and can be used for silence detection.