DTMF tones | 33 |
DTMF tones
The numeric keys of the phone (0 to 9,* and #) always trans- mit DTMF tones (DualTone MultiFrequency) also known as
“touch tones ”. DTMF tones are used by certain telephone services such as answering machines,pagers,etc.
Rather than keying in a separate code after each of a series of requests,you can carry out complex operations in one go.
e.g.To reach ‘Listen to new messages’ in one go
An answering machine has the following characteristics: phone number 12345, password 9876, code 3 to activate the function ‘Listen to new messages’.
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■Enter 12345, 12345 is displayed.
■Press and hold 
to enter a wait character. 12345w is displayed.
■Enter 9876, 12345w9876 is displayed.
■Press and hold 
to enter a pause character, 12345w9876p is displayed.