> 18.6 | AT+VTD Tone duration

> 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(s)
> +VTD: (list of supported<duration>s)
> OK

> Read Command AT+VTD?
> Response(s)
> <duration>
> OK

> Write Command AT+VTD=<duration>
> Response(s)
> OK
> ERROR
> +CME ERROR

> Reference(s) |  | PIN |  | ASC0 | ASC1 | USB | MUX1 | MUX2 | MUX3 |  |  | Charge | Q | Last
> GSM 07.07 |  | - |  | + | + | + | + | + | + |  |  | - | - | -

> Parameter Description

> <duration>(num)

> Duration of the DTMF signal in 1/10 seconds with tolerance.
> The minimum duration of DTMF signals is 300ms.
> 1(&F)(P)...255