What is the command used to enable / disable DTMF tone detection?

Command: #VTD
Function: DTMF Tone Reporting
Values: i, j, k (three ASCII hexadecimal bit maps)
Default: 3F, 3F, 3F
Result Codes: OK if bits supported with #VTD=? are selected; ERROR otherwise.
Description: The #VTD command queries and controls which types of tones can be detected and reported to the DTE via shielded codes in Voice Transmit, Voice Receive, and Online Voice Command modes.

Command options are:

#VTD? Returns the current setting for the #VTD command.
#VTD=? Returns the tone reporting capabilities of the modem.
#VTD= i,j,k Where i,j,k corresponds (in ASCII hexadecimal) to the desired capabilities, for Voice Transmit, Voice Receive, and Online Voice Command modes, respectively.

#VTD Tone Detection/Responding Bit Settings
Bit - Description
0 0 - Disable DTMF capability;
1 - Enable DTMF tone capability 1.
1 0 - Disable V.25 1300 Hz Calling tone capability;
1 - Enable V.25 1300 Hz Calling tone capability 1.
2 0 - Disable T.30 1100 Hz Facsimile Calling tone capability;
1 - Enable T.30 1100 Hz Facsimile Calling tone capability 1.
3 0 - Disable V.25/T.30 2100 Hz Answer tone capability;
1 - Enable V.25/T.30 2100 Hz Answer tone capability 1.
4 0 - Disable Bell 2225 Hz Answer tone capability;
1 - Enable Bell 2225 Hz Answer tone capability 1.
5 0 - Disable call progress tone and cadence (i.e., busy and dial tone) capability;
1 - Enable call progress tone and cadence (i.e., busy and dial tone) capability 1.
6-7 - Reserved.

Notes:
1. The modem detects this tone/cadence, and reports it via a shielded code to the DTE.
2. Tone detection is only performed when the sampling rate is 7.2 kHz (see the #VSR command).