Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 176)

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176 Rev. 1.3
+VRN
Ringing Tone Never Appeared Timer
This command sets the amount of time in seconds the DCE will wait looking for Ring-
ing Tone. If the DCE does not detect Ringing Tone in this time period, the DCE shall
assume that the remote station has gone off-hook and return an OK result code.
Default time is 0 seconds.
+VRX
Receive Voice Stream
Enable DTE receive of voice stream. The DCE will return a CONNECT response fol-
lowed by the voice stream as defined by the +VSM command. The DTE can issue a
<DLE><!> or <DLE><ESC> sequence to terminate the receive stream. The DCE will
return a <DLE><ETX> followed by an OK response for <DLE><!> and <DLE><ESC>
followed by an OK response for <DLE><ESC>. The DCE can be configured to termi-
nate the stream using the DTE/DCE Inactivity Timer, which is configured using the
+VIT command. The DTE will need to process any <DLE> shielded events present in
the data stream. Any <DLE><DLE> sequences can be preserved to allow less over-
head during playback of the stream with the +VTX command.
+VSD = <sds>, <sdi>
Silence Detection
<sds>
Silence Detection Sensitivity
118 More sensitive: lower noise levels considered to be silence
128 Nominal level of sensitivity.
138 Less sensitive: higher noise levels considered to be silence
<sdi> Silence Detection Interval
The time interval in 0.1 second units, which must contain no or little activity, before the
DCE will report (QUIET) (<DLE><q>). Default is five seconds.
+VSM = <cml>
Compression Selection Method
<cml>
Compression Mode
0 Signed linear PCM, 8-bit, 64 kbps
1 Unsigned linear PCM, 8-bit, 64 kbps
4 G.711U
-law companding PCM, 8-bit, 64 kbps
5 G.711A A-law companding PCM, 8-bit, 64 kbps
129 G.726 ADPCM, 2-bit, 16 kbps
131 G.726 ADPCM, 4-bit, 32 kbps
All compression modes use a fixed sampling rate of 8 kHz. See 10.2.8.2 of V.253 for
an explanation of the +VSM=? command results.
+VSP = <mode>
Voice Speakerphone State
<mode>
Description
0 Speakerphone AEC, AES and LEC disabled. Handset FIR filter
coefficients are selected.
1
Speakerphone AEC, AES and LEC enabled. Speakerphone FIR filter
coefficients are selected. The +VLS=13 command must be used in combination with
this setting.
+VTD = <dur>
DTMF / Tone Duration Timer
This command sets the default DTMF / tone generation duration in 10 ms units for the
+VTS command. Default time is 1 second (<dur> = 100).
Table 110. Extended AT+ Command Set (Continued)
Command Action