User guide

August 2001 29
Sending and Receiving Digits
Sending and Receiving Digits
Handling Rotary Digits
Boards with VP resources can receive rotary digits but cannot
dial rotary digits.
Each phone is connected to a line with unique electrical
characteristics, and phones send digits with slightly different
timing. For the application to properly receive rotary digits from
different phones, it must train to recognize the way that phone
sends rotary pulses. The best way to recognize the digits is to
train at the beginning of a call by asking the caller to press ‘0’ if
they have a rotary phone. The application then uses the ‘0’ digit
to learn the timing of that phone. The application can then
recognize any rotary digits from that phone.
Use the following procedure to receive rotary digits:
1. Specify what type of digits the application receives using
RHT_SET_DIGIT_MODE.
Set the mode to EN_ROTARY to receive rotary digits. You
can specify that your application also receive DTMF or
MF digits.
2. Train rotary digits using RHT_TWAIT_DIGIT or
RHT_PRE_REC.
These functions both use the data structure VPstartStop_s,
which has a field for rotary training. Set that field to train
on digit ‘7’, ‘8’, ‘9’, or ‘0’. For most operations, ‘0’ provides the
best training. In the application, ask customers to dial the
digit you specify in VPstartStop_s.
3. Check the status of rotary training using
RHT_GET_ROTARY_INFO.
4. Receive rotary digits using RHT_TWAIT_DIGIT,
RHT_READ_DIGIT, RHT_PLAY, or RHT_REC.
Once you have trained the application to recognize pulse
characteristics from that phone, it can recognize any rotary
digit.