User guide

30 RealCT Direct API Developer Guide
Chapter 2: Digit Handling
Handling DTMF and MF Digits
To send and receive DTMF and MF tones, use the following
procedure:
1. Specify what type of digits the application receives using
RHT_SET_DIGIT_MODE.
Set the mode to
EN_DTMF for DTMF digits or EN_MF for
MF digits.
You can enable rotary detection with DTMF or MF
detection, but the application cannot detect both MF and
DTMF digits. The two signaling methods use similar
frequencies, which could lead to inaccurate signal detection.
2. Receive tones using RHT_TWAIT_DIGIT or
RHT_READ_DIGIT.
These functions use the RHT_SET_DIGIT_MODE to
determine what type of digit to receive.
RHT_TWAIT_DIGIT and RHT_READ_DIGIT clear the
digit from the digit buffer.
3. Send digits using RHT_DIAL.
If you specify a VP device, RHT_DIAL sends DTMF digits
by default. To send MF digits, use an ‘M’ in the string passed
to RHT_DIAL. To specify DTMF digits, use a ‘T’ in the
string. For example, the string “123M456T7” specifies
DTMF digits 1, 2, 3, then MF digits 4, 5, 6, then DTMF
digit 7.