Specifications

Chapter 16 – Audio Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 267
16.12 AT^SNFI Set Microphone Path Parameters
Description: AT^SNFI controls the microphone path amplification. Read and write options of this command
refer to the active audio mode. The write command works only in audio modes 2 to 6.
Syntax: Test Command: AT^SNFI=?
Response: ^SNFI: (list of supported <inBbcGain>s) , (list of supported <inCalibrate>s)
OK
Read Command: AT^SNFI?
Response: ^SNFI: <inBbcGain>, <inCalibrate>
OK
ERROR
+CME ERROR: <err>
Write Command: AT^SNFI=<inBbcGain>, <inCalibrate>
Response: OK
ERROR
+CME ERROR: <err>
Parameters:
<inBbcGain>
ADC gain adjustable in eight 6 dB steps from 0 dB to 42 dB (0=0dB, 7=42dB, 8 steps of 6 dB).
0...7
<inCalibrate>
Multiplication factor for input samples. Formula to calculate the negative gain (attenuation) of the input signal:
Gain in dB = 20 * log (inCalibrate / 32768)
0...32767
Notes:
• The range of <inCalibrate> is up to 65535 but will be suppressed to 32767. Values above <inCalibrate>=
65535 will cause a failure.
• The parameter <inCalibrate> of AT^SNFI is identical with <atten> of AT^SNFA.
• For use after restart, changed values can be stored with AT^SNFW.
• Attention! When you adjust audio parameters avoid exceeding the maximum allowed level. Bear in mind that
exposure to excessive levels of noise can cause physical damage to users!
• This command is not PIN protected.
• This command is supported in airplane mode.
16.13 AT^SNFM Set Microphone Audio Path
Description: The read command returns the microphone mute and supply voltage status.
The microphone can be muted or activated by changing <MicSwitch> in all audio modes (1 to 6)
and during a voice call only. As an alternative, you can use the AT+CMUT command to mute the
microphone.
Syntax: Test Command: AT^SNFM=?
Response: ^SNFM: (list of supported <MicSwitch>s)
OK
Read Command: AT^SNFM?
Response: ^SNFM: <MicSwitch>
OK
ERROR
+CME ERROR: <err>
Write Command: AT^SNFM=[<MicSwitch>]
Response: OK
ERROR
+CME ERROR: <err>
Parameter:
<MicSwitch> Microphone mute control parameter.
Evaluated during voice calls and if <MicVccCtl> is omitted only (e.g., AT^SNFM=1).
Command does not depend on audio mode.
0 Mutes the microphone.
2 Activates the microphone. Default.
Notes:
• This command is not PIN protected.
• This command is supported in airplane mode.