cdiStartTones

Starts the transmission of a single or double-cadenced dual tone.

Prototype

DWORD cdiStartTones ( CTAHD ctahd, CDI_TONE_PARMS *parms)

Argument

Description

ctahd

Context handle.

parms

Pointer to a structure specifying the frequency, cadence, and iterations of the tone:

typedef struct
{
   DWORD     size;
   DWORD     freq1;
   DWORD     freq2;
   INT32     ampl1;
   INT32     ampl2;
   DWORD     ontime;
   DWORD     offtime;
   DWORD     ontime2;
   DWORD     offtime2;
   INT32     iterations;
} CDI_TONE_PARMS

Refer to CDI_TONE_PARMS for a description of these fields.

Return values

Return value	Description
SUCCESS
CTAERR_BAD_ARGUMENT	Argument is not in the valid range.
CTAERR_FUNCTION_ACTIVE	Function was already invoked.
CTAERR_INVALID_CTAHD	Handle is invalid.
CTAERR_INVALID_STATE	Port must be off-hook to invoke this function.

Events

Event	Description
CDIEVN_TONE_DONE	Tone transmission is complete.

Details

When a station is off-hook, you can transmit tones to the station. Each tone can consist of one or two frequency components, each at different amplitudes. You can also set up a pattern (cadence) of up to two iterations of the tone, each of different lengths.

To start the transmission of a tone, invoke cdiStartTones. In the invocation, pass a pointer to the CDI_TONE_PARMS structure. The following illustration shows how the parameters in CDI_TONE_PARMS determine the cadence:

Cadence parameters

When enhanced mode is enabled, the DSP automatically stops tones upon detection of on-hook or DTMF. Otherwise, invoke cdiStopTones to stop an ongoing tone.

Note: If the board enters the protection state (due to overheating), all stations receive an alarm tone indicating maintenance attention is needed. This tone overrides any other tones.

Refer to Transmitting tones for more information.