Specifications

Chapter 16 – Audio Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 262
16.6 AT+VTD Tone Duration
Description: This command refers to an integer <duration> that defines the length of tones transmitted with
the AT+VTS command.
Syntax: Test Command: AT+VTD=?
Response: +VTD: (list of supported<duration>s)
OK
Read Command: AT+VTD?
Response: <duration>
OK
ERROR
ERROR: <err>
Write Command: AT+VTD=<duration>
Response: OK
ERROR
ERROR: <err>
Parameter:
<duration>
Duration of the DTMF signal in 1/10 seconds with tolerance.
The minimum duration of DTMF signals is 300ms.
1...255 Default=1. This is the factory default value and can be restored to '1' with AT&F. It is also a powerup
default which is not stored at power down.
Notes:
• This command is not PIN protected.
• This command is not supported in airplane mode.
16.7 AT+VTS DTMF and Tone Generation
Description: AT+VTS is intended to send ASCII characters or strings which cause the Mobile Switching
Center (MSC) to transmit DTMF tones to a remote subscriber. The command can only be used
during active voice calls and offers the following variants:
• AT+VTS=<dtmfString> allows to send a sequence of DTMF tones with a duration defined
with AT+VTD.
• AT+VTS=<dtmf>[,<duration>] allows to send a single DTMF tone. In this case, the duration
can be individually determined during the call.
Syntax: Test Command: AT+VTS=?
Response: +VTS: (list of supported<dtmf>s), (list of supported<duration>s)
OK
Write Command: AT+VTS=<dtmfString>
Response: OK
ERROR
ERROR: <err>
Write Command: AT+VTS=<dtmf>[, <duration>]
Response: OK
ERROR
ERROR: <err>
Parameters:
<dtmfString> String of ASCII characters in the set 0-9,#,*,A, B, C, D. Maximal length of the string is 29.
The string must be enclosed in quotation marks (“...”).
<dtmf> ASCII character in the set 0...9,#,*, A, B, C, D.
<duration> Tone duration in 1/10 seconds with tolerance. If not specified current setting of AT+VTD is
used.
The minimum duration of DTMF signals is 300ms.
1...255
Notes:
• This command is not PIN protected.
• This command is not supported in airplane mode.