Digit Monitoring

Digit monitoring monitors the call for digits. TSPI enables signaling of digits in two modes:

• Pulse Digits are signaled as pulse/rotary sequences. For detection, these pulses manifest themselves as nothing more than sequences of audible clicks. Valid pulse digits are '0' through '9'.
• DTMF Digits are signaled as DTMF (Dual Tone Multi-Frequency) tones. Valid DTMF digits are '0' through '9', 'A'. 'B', 'C', 'D', '*', and '#'. Both the beginning and the down edge of DTMF digits can be monitored.

Digit monitoring can be enabled or disabled on a specified call with TSPI_lineMonitorDigits. If enabled, all detected digits cause tapi32.dll to be notified in the LINE_MONITORDIGITS callback message. The callback provides the call handle on which the digit was detected as well as the digit value and the digit mode. The scope of digit monitoring is bound by the lifetime of the call. Digit monitoring on a call ends as soon the call disconnects or goes idle.