76 Voice API Programming Guide — June 2005
Call Progress Analysis
ATDX_FRQDUR2( )
Duration of the tone detected in the tone detection range specified by the DX_CAP
ca_lower2frq and ca_upper2frq parameters; usually the second tone of an SIT sequence (10
msec units).
ATDX_FRQHZ3( )
Frequency in Hz of the tone detected in the tone detection range specified by the DX_CAP
ca_lower3frq and ca_upper3frq parameters; usually the third tone of an SIT sequence.
ATDX_FRQDUR3( )
Duration of the tone detected in the tone detection range specified by the DX_CAP
ca_lower3frq and ca_upper3frq parameters; usually the third tone of an SIT sequence (10
msec units).
7.15.4 Global Tone Detection Tone Memory Usage
The information in this section does not apply to DM3 boards.
If you use call progress analysis to identify the tri-tone SIT sequences, call progress analysis will
create tone detection templates internally, and this will reduce the number of tone templates that
can be created using Global Tone Detection functions. See Chapter13, “Global Tone Detection and
Generation, and Cadenced Tone Generation” for information relating to memory usage for Global
Tone Detection.
Call progress analysis will create one tone detection template for each single-frequency tone with a
100 Hz detection range. For example, if detecting the set of tri-tone SIT sequences (three
frequencies) on each of four channels, the number of allowable user-defined tones will be reduced
by three per channel.
If you initiate call progress analysis and there is not enough memory to create the SIT tone
detection templates internally, you will get a CR_MEMERR error. This indicates that you are
trying to exceed the maximum number of tone detection templates. The tone detection range
should be limited to a maximum of 100 Hz per tone to reduce the chance of exceeding the available
memory.
7.15.5 Frequency Detection Errors
The information in this section does not apply to DM3 boards, as the DX_CAP fields mentioned in
this section are not supported on DM3 boards.
The frequency detection range specified by the lower and upper bounds for each tone cannot
overlap; otherwise, an error will be produced when the driver attempts to create the internal tone
detection templates. For example, if ca_upperfrq is 1000 and ca_lower2frq is also 1000, an overlap
occurs and will result in an error. Also, the lower bound of each frequency detection range must be
less than the upper bound (for example, ca_lower2frq must be less than ca_upper2frq).