Longshine LCS-8560C1 - Manual (Page 215)

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
102184B Conexant 5-25
+VGM - Microphone Gain
This command causes the modem to set the microphone gain of the speakerphone
function.
Syntax
+VGM=<gain>
Defined Values
<gain> Decimal number between 0 and 255 corresponding to the gain.
Reporting Current or Selected Values
Command: +VGM?
Response: <gain>
Example: 64 For the default setting.
Reporting Supported Range of Parameter Values
Command: +VGM=?
Response: <gain> range
Example: 0-255
Result Codes
OK <gain> = 0-255.
ERROR Otherwise, or if not in Voice Mode with speakerphone
enabled (+VSP=1).