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GE863-GPS Software User Guide
1vv0300724 Rev. 2 - 24/01/07
3.3 DTMF tones
DTMF tones are managed by specific AT commands. These tones are generated with AT commands
only during voice calls. The minimum duration of a DTMF tone can be set on 10 ms but it should be
considered that this value can vary with the limitations on network.
Group high
Group low
1209 Hz 1336 Hz 1477 Hz
697 Hz 1 2 3
770 Hz 4 5 6
852 Hz 7 8 9
941 Hz * 0 #
NOTE: The GSM system architecture defines that the audio signal of the DTMF tones is inserted by
the network switches on commands sent by the Mobile Station (MS). Thus, the default duration
parameters may vary from network to network. In case that the devices to be controlled by DTMF are
sensitive related to the duration of the tones and timing of the sequences, dedicated investigations on
the parameter settings have to be made.
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