62 Voice API Programming Guide — June 2005
Call Progress Analysis
•DX_PAMDENABLE. Enables PAMD, PVD, and fax tone detection.
•DX_PAMDOPTEN. Enables PAMD, PVD, DX_OPTNOCON, and fax tone detection.
Note: DX_OPTEN and DX_PVDOPTEN are obsolete. Use DX_OPTNOCON and
DX_PVDOPTNOCON instead.
For more information on adjusting DX_CAP parameters, see Section 7.11, “Call Progress Analysis
Tone Detection on Springware Boards”, on page65, Section 7.12, “Media Tone Detection on
Springware Boards”, on page69, and Section 7.15, “SIT Frequency Detection (Springware Only)”,
on page 72.
7.10.3 Enabling Call Progress Analysis
Call progress analysis is activated on a per-channel basis. On Springware boards, initiate call
progress analysis using the dx_initcallp() function.
On Springware boards, to enable call progress analysis on a specified channel, perform the
following steps. This procedure needs to be followed only once per channel; thereafter, any
outgoing calls made using a dial function will benefit from call progress analysis.
1. Make any desired modifications to the default dial tone, busy tone, fax tone, and ringback
signal definitions using the dx_chgfreq(), dx_chg dur( ), and dx_chgrepcnt( ) functions. For
more information, see Section 7.14, “Modifying Default Call Progress Analysis Tone
Definitions on Springware Boards”, on page 71.
2. Call dx_deltones( ) to clear all tone templates remaining on the channel. Note that this
function deletes all global tone definition (GTD) tones for the given channel, and not just those
involved with call progress analysis.
3. Execute the dx_initcallp( ) function to activate call progress analysis. Call progress analysis
stays active until dx_deltones() is called.
The dx_initcallp( ) function initializes call progress analysis on the specified channel using the
current tone definitions. Once the channel is initialized with these tone definitions, this
initialization cannot be altered. The only way to change the tone definitions in effect for a given
channel is to issue a dx_deltones() call for that channel, then invoke another dx_initcallp( ) with
different tone definitions.
7.10.4 Executing a Dial Function
To use call progress analysis, call dx_dial() with the mode function argument set to DX_CALLP.
Termination of dialing with call progress analysis is indicated differently depending on whether the
function is running asynchronously or synchronously.
If running asynchronously, use Standard Runtime Library (SRL) Event Management functions to
determine when dialing with call progress analysis is complete (TDX_CALLP termination event).
If running synchronously, wait for the function to return a value greater than 0 to indicate
successful completion.