150 Voice API Programming Guide — June 2005
Global Tone Detection and Generation, and Cadenced Tone Generation

Tips and Hints for Building Tone Templates

The following are tips and hints when building a tone template for global tone detection:
•After using a build-tone function to define a new tone template, you must call dx_addtone()
to add the tone template to a channel and enable detection of that tone on a channel.
•After using a build-tone function to define a tone template, if the template is not added to a
channel, the next call to a build-tone function will overwrite the tone definition contained in
the previous template.
•Only one tone template can be created at a time; however, multiple tone templates can be
added to a channel. Each channel can have a different set of tone templates. Once created, tone
templates can be selectively disabled or enabled by using dx_distone() and dx _enbtone( ).
See Section 13.1.5, “Working with Tone Templates”, on page150 for more information.
•Each tone template must have a unique tone ID.
•On Windows, do not use tone IDs 261, 262 and 263; they are reserved for library use.
•A particular tone template that has been added to a channel cannot be changed or deleted. A
tone template can be disabled on a channel, but to delete a tone template, all tone templates on
that channel must be deleted. See Section13.1.5, “Working with Tone Templates”, on
page 150 for more information.
Table14 lists some standard Bell System Network call progress tones. The frequencies are useful
to know when creating tone templates.
13.1.5 Working with Tone Templates
After building a tone template, use the following functions to add/delete tone templates or to
enable/disable tone detection:
dx_addtone( )
Adds a tone template that was defined by the most recent build-tone function call to the
specified channel. Adding a tone template to a channel downloads it to the board and enables
detection of tone-on and tone-off events for that tone template.
Table14. Standard Bell System Network Call Progress Tones
Tone Frequency (Hz) On Time (msec) Off Time (msec)
Dial 350 + 440 Continuous
Busy 480 + 620 500 500
Congestion (Toll) 480 + 620 200 300
Reorder (Local) 480 + 620 300 200
Ringback 440 + 480 2000 4000