Specifications

Chapter 15 – Audio Commands
Multi-Tech Systems, Inc. CDMA C1 AT Commands Reference Guide 85
Use these audio commands only with the SocketModem model MTSMC-C1-V, which includes microphone input
and speaker output.
Audio Subsystem Overview
The audio sub-system block diagram below indicates where the various gains and AT commands take effect.
Since the AT command values are saved separately for each audio path, the audio gains should be tuned
independently for each audio path. Note that the +CLVL is intended to operate like a volume control, so it
should be set to 0dB gain during the tuning process (this is the default value).
Tuning Audio
Audio parameters need to be set for each device connected to the audio sub-system. The audio parameters are
saved independently for the audio path: Analog 2. Tune the audio parameters using the procedures detailed
below.
Analog
1. Select the relevant audio path, and issue the AT+VIP command the set the audio parameters to their default
values.
2. Set +MGE so that the microphone output plus MGE gain is 23dB to 25dB below 2.828Vpp.
3. Make a voice call.
4. Adjust +VGT to appropriate levels.
5. Adjust +VGR to appropriate levels.