Quectel EC25

LTE Module Series
EC25&EC21 AT Commands Manual
EC25&EC21_AT_Commands_Manual 190 / 231
Parameter
This parameter will not be saved.
12.4. AT+VTS DTMF and Tone Generation
The command is used to send ASCII characters which cause MSC to transmit DTMF tones to a remote
subscriber. It can only be operated in voice call.
OK
Read Command
AT+QAUDLOOP?
Response
+QAUDLOOP: <enable>
OK
Write Command
AT+QAUDLOOP=<enable>
Response
OK
ERROR
Maximum Response Time
300ms
<enable> Numeric type. To enable or disable audio loop test
0 Disable audio loop test
1 Enable audio loop test
AT+VTS DTMF and Tone Generation
Test Command
AT+VTS=?
Response
+VTS: (0-9,A-D,*,#),(0-255)
OK
Write Command
AT+VTS=<dtmfstring>[,<duration>]
Response
OK
ERROR
If there is any error related to ME functionality:
+CME ERROR: <err>
Maximum Response Time
Depends on the length of <dtmfstring> and <duration>.
NOTE