Longshine LCS-8156C1 - Manual (Page 174)

AT Commands for CX930xx Modem Reference Manual
5-10 Conexant 102752B
+VGT - Voice Gain Transmit (Playback Volume)
This command causes the modem to set the volume level.
Syntax
+VGT=
Defined Values
Decimal number corresponding to the volume level.
Reporting Current or Selected Values
Command: +VGT?
Response:
Example: 128 For the default setting.
Reporting Supported Range of Parameter Values
Command: +VGT=?
Response: range
Example: 0-255
Result Codes
OK = 0-255.
ERROR Otherwise, or if not in Voice Mode.