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<TITLE>ZyXEL Voice AT Commands</TITLE>
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<B><FONT SIZE=+3>Z</FONT>YXEL <FONT SIZE=+2>V</FONT>OICE <FONT SIZE=+1>AT</FONT> <FONT SIZE=+2>C</FONT>OMMANDS</B>
<HR SIZE=4>
The U-1496 series modems support a set of voice AT commands. These commands
are basically consistent with the TIA TR29.2 committee IS-101 document. The
command implementation is not final as of this writing. It is certain that it
will be continually updated during the initial stage. Please refer to the
manual amendment or firmware release notes in the software disk accompanying
this modem for updated detail.
<P>
The following is a list of the voice and voice-related AT commands:
<UL>
<LI><A HREF="#AT+FCLASS=">AT+FCLASS=<I>mode</I></A>
<LI><A HREF="#AT+FCLASS?">AT+FCLASS?</A>
<LI><A HREF="#AT+FCLASS=?">AT+FCLASS=?</A>
<LI><A HREF="#ATA">ATA (with AT+FCLASS=8)</A>
<LI><A HREF="#ATD">ATD (with AT+FCLASS=8)</A>
<LI><A HREF="#ATH">ATH (with AT+FCLASS=8)</A>
<LI><A HREF="#ATFLO">AT+FLO=<value></A>
<LI><A HREF="#ATFLO?">AT+FLO?</A>
<LI><A HREF="#ATFLO=?">AT+FLO=?</A>
<LI><A HREF="#ATZ">ATZ</A>
<LI><A HREF="#AT+VBT=">AT+VBT=<I>value</I></A>
<LI><A HREF="#AT+VBT?">AT+VBT?</A>
<LI><A HREF="#AT+VBT=?">AT+VBT=?</A>
<LI><A HREF="#AT+VDD">AT+VDD=<I>value</I></A>
<LI><A HREF="#AT+VDD?">AT+VDD?</A>
<LI><A HREF="#AT+VDD=?">AT+VDD=?</A>
<LI><A HREF="#AT+VDH=">AT+VDH=<I>value</I></A>
<LI><A HREF="#AT+VDH?">AT+VDH?</A>
<LI><A HREF="#AT+VDH=?">AT+VDH=?</A>
<LI><A HREF="#AT+VGT=">AT+VGT=<I>value</I></A>
<LI><A HREF="#AT+VGT?">AT+VGT?</A>
<LI><A HREF="#AT+VGT=?">AT+VGT=?</A>
<LI><A HREF="#AT+VIP">AT+VIP</A>
<LI><A HREF="#AT+VIT">AT+VIT=<I>value</I></A>
<LI><A HREF="#AT+VIT?">AT+VIT?</A>
<LI><A HREF="#AT+VIT=?">AT+VIT=?</A>
<LI><A HREF="#AT+VLS=">AT+VLS=<I>device</I></A>
<LI><A HREF="#AT+VLS?">AT+VLS?</A>
<LI><A HREF="#AT+VLS=?">AT+VLS=?</A>
<LI><A HREF="#AT+VNH=">AT+VNH=<I>value</I></A>
<LI><A HREF="#AT+VNH?">AT+VNH?</A>
<LI><A HREF="#AT+VNH=?">AT+VNH=?</A>
<LI><A HREF="#AT+VRA=">AT+VRA=<I>value</I></A>
<LI><A HREF="#AT+VRA?">AT+VRA?</A>
<LI><A HREF="#AT+VRA=?">AT+VRA=?</A>
<LI><A HREF="#AT+VRN=">AT+VRN=<I>value</I></A>
<LI><A HREF="#AT+VRN?">AT+VRN?</A>
<LI><A HREF="#AT+VRN=?">AT+VRN=?</A>
<LI><A HREF="#AT+VRX">AT+VRX</A>
<LI><A HREF="#AT+VSD=">AT+VSD=<I>sds</I>,<I>sdi</I></A>
<LI><A HREF="#AT+VSD?">AT+VSD?</A>
<LI><A HREF="#AT+VSD=?">AT+VSD=?</A>
<LI><A HREF="#AT+VSM=">AT+VSM=<I>cml</I></A>
<LI><A HREF="#AT+VSM?">AT+VSM?</A>
<LI><A HREF="#AT+VSM=?">AT+VSM=?</A>
<LI><A HREF="#AT+VSY=">AT+VSY=<I>value</I></A>
<LI><A HREF="#AT+VSY?">AT+VSY?</A>
<LI><A HREF="#AT+VSY=?">AT+VSY=?</A>
<LI><A HREF="#AT+VTS">AT+VTS=<I>string</I></A>
<LI><A HREF="#AT+VTS=?">AT+VTS=?</A>
<LI><A HREF="#AT+VTX">AT+VTX</A>
<LI><A HREF="#AT+VVT=">AT+VVT=<I>value</I>
<LI><A HREF="#AT+VVT?">AT+VVT?</A>
</UL>
<P><HR WIDTH=65% ALIGN=right>
<B><FONT SIZE=+2>C</FONT>OMMAND <FONT SIZE=+2>S</FONT>YNTAX</B>
<P>
AT is used as the command line prefix, the voice command takes one of the
following forms:
<PRE>
+V<CM>? read current setting
+V<CM>=? read permissable setting
+V<CM>=<<I>single value</I>> set single-valued parameter
+V<CM>=<<I>value string</I>> set compound parameter
</PRE>
where <CM> represents a two-letter command syntax, a
<I>value string</I> consists
of values separated by comma or semicolon. The first two comand forms are
for read action, the last two are for write action. A command may have both
action types or just read or write type only.
<P><HR WIDTH=65% ALIGN=right>
<B><FONT SIZE=+2>R</FONT>ESPONSE <FONT SIZE=+2>S</FONT>YNTAX</B>
<P>
For each command line received, the modem issues a response to each command in
the command line followed by a final response.
<P>
Each command response is of the form:
<PRE>
<CR><LF>
<value> or <value range> response of "?" or "=?" command
<CR><LF>
</PRE>
The final response is
<PRE>
<CR><LF>
OK or ERROR Command line response
<CR><LF>
</PRE>
The final response is " OK " if all the commands in the command line have
been successfully executed, otherwise it is "ERROR".
<P><HR WIDTH=65% ALIGN=right>
<B><FONT SIZE=+2>S</FONT>UPPORTED <FONT SIZE=+2>C</FONT>OMMANDS FOR <FONT SIZE=+2>V</FONT>OICE <FONT SIZE=+2>M</FONT>ODE <FONT SIZE=+2>O</FONT>PERATION</B>
<H3><A NAME="AT+FCLASS=">AT+FCLASS=<I>mode</I></A></H3>
<OL>
This command selects a DCE mode as follows:
<PRE>
<I>mode</I> = 0 (Default), Data mode.
<I>mode</I> = 2, Class 2 Fax mode.
<I>mode</I> = 2.0, Class 2.0 Fax mode.
<I>mode</I> = 6, ZFax mode.
<I>mode</I> = 8, Voice mode.
DCE Result codes:
OK: Command is accepted.
ERROR: <I>mode</I> is not permitted.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+FCLASS?">AT+FCLASS?</A></H3>
<OL>
DCE will return current mode setting, followed by the OK result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+FCLASS=?">AT+FCLASS=?</A></H3>
<OL>
DCE will return permitted modes. The response is:
<PRE>
0,2,2.0,6,8
OK
</PRE>
with <CR><LF> between each line.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="ATA">ATA (with AT+FCLASS=8)</A></H3>
<OL>
This command causes DCE to answer the phone. DCE will return VCON
result code immediately.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="ATD">ATD (with AT+FCLASS=8)</A></H3>
<OL>
This command causes the DCE to dial a phone number.
<P>
Result codes:
<PRE>
VCON: The DCE issues this result code when the DCE
has determined that the remote station is off hook.
NO ANSWER: The DCE issues this result code when the DCE has
continuously detected Ringbacks for the S7 specified
amount of time.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="ATH">ATH (with AT+FCLASS=8)</A></H3>
<OL>
This command causes the DCE to hang up the phone with the following
considerations for a hang up while in Voice mode:
<UL>
<LI> Force the command AT+FCLASS=0, but will not destroy any of the
Voice parameters.
<LI> Force voice I/O device to Telco line.
</UL>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="ATFLO">AT+FLO=<value></A></H3>
<OL>
This parameter allows the DTE to identify and select the type(s) of
flow control provided and used.
<P>
The range of the <value> is from 1 to 2.
<PRE>
1 -> Use XON/XOFF flow control in either direction
2 -> Use CCITT Circuit 133 for flow control of the DCE by the DTE,
use CCITT Circuit 106 for flow control of the DTE by the DCE.
</PRE>
Default value is 1.
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <value> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="ATFLO?">AT+FLO?</A></H3>
<OL>
DCE will return current flow control mode followed by the OK result
code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="ATFLO=?">AT+FLO=?</A></H3>
<OL>
DCE will return permitted flow control modes.
<P>
The response is:
<PRE>
0-2
OK
</PRE>
with <CR><LF> between each line.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="ATZ">ATZ</A></H3>
<OL>
This command causes the DCE to enter DATA MODE (AT+FCLASS=0) and
set all of the voice related parameters to their default values.
</OL>
<HR WIDTH=65% ALIGN=right>
<B><FONT SIZE=+2>V</FONT>OICE <FONT SIZE=+2>M</FONT>ODE <FONT SIZE=+2>C</FONT>OMMANDS</B>
<H3><A NAME="AT+VBT=">AT+VBT=<I>value</I></A></H3>
<OL>
This command causes the DCE to set the default DTMF/tone generation
duration used in conjunction with the AT+VTS command.
<P>
The range of <value> is 1-255. The units are 0.1 seconds.
<P>
<PRE>
DCE Result codes:
OK: if DCE accepts this command.
ERROR: if <I>value</I> parameter is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VBT?">AT+VBT?</A></H3>
<OL>
DCE will return current beep duration setting, followed by the OK
result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VBT=?">AT+VBT=?</A></H3>
<OL>
DCE will return permitted values of beep duration. The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VDD">AT+VDD=<I>value</I></A></H3>
<OL>
This command sets the duration of a continous tone (DTMF) that must be
present before the DCE will recognizes it and report it as a valid
tone. This is in 5msec units.
<P>
The range of the <value> is from 0 to 255.
Default value is 6.
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <I>value</I> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VDD?">AT+VDD?</A></H3>
<OL>
DCE will return current duration of a continous tone (DTMF),
followed by the OK result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VDD=?">AT+VDD=?</A></H3>
<OL>
DCE will return permitted duration of a continous tone (DTMF).
<P>
The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>
Note: This is not defined in IS-101. Once again this was requested by
customers who were using the modem in overseas countries where
the duration of a DTMF tone is not standard.
</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VDH=">AT+VDH=<I>value</I></A></H3>
<OL>
This command sets the threshold of the DTMF tone detection. Lowering
the value increas the sensitivity. Please note that increasing the
sensitivity by too much would cause false alarms where sounds could
be intepreted as DTMF tones.
<P>
The range of the <value> is from 0 to 31.
Default value is 16.
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <I>value</I> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VDH?">AT+VDH?</A></H3>
<OL>
DCE will return current threshold of the DTMF tone detection, followed
by the OK result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VDH=?">AT+VDH=?</A></H3>
<OL>
DCE will return permitted threshold of the DTMF tone detection.
<P>
The response is:
<PRE>
0-31
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>
NOTE: This is not defined in IS-101. This command was added to enable
the DCE to either increase or decrease its sensitivity to DTMF
tones by defining the range of the threshold. This feature was
added due to requests from customers.
</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VGT=">AT+VGT=<I>value</I></A></H3>
<OL>
This command causes the DCE to set the volume level for the
transmitted voice samples.
<P>
The range of the <I>value</I> is from 0 to 255.
The default value is 192.
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <value> parameter is out of
range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VGT?">AT+VGT?</A></H3>
<OL>
DCE will return current volume level, followed by the OK result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VGT=?">AT+VGT=?</A></H3>
<OL>
DCE will return permitted values of volume level. The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VIP">AT+VIP</A></H3>
<OL>
This command causes the DCE to initialize all the Voice parameters
to the default settings as follows:
<PRE>
Compression method : 2-bit ADPCM
Silent threshold : 15
Activity Timer : 7 sec.
Silence interval : 7 sec.
Ringback gone away timer : 7 sec.
Ringback never appeared timer : 5.7 sec.
Default beep tone duration : 1 sec.
Transmit Volume Selection : 192
Default resync timer : 50ms
Default VCON timer : 16
Default DTMF det interval timer: 30ms
Default DTMF det threshold : 16
Indicate S/W flow control : Software
</PRE>
DCE Result codes:
<PRE>
OK if DCE accepts this command.
ERROR if the DCE is not connected to at least one Voice
I/O device.
</PRE>
<CITE>Note: Complies with the IS-101</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VIT">AT+VIT=<I>value</I></A></H3>
<OL>
This command sets the DCE's initial value for the DTE/DCE Inactivity
timer.
<P>
The range of the <I>value</I>; is from 0 to 255. The units are 1 second.
Default value is 7 sec.
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <I>value</I> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VIT?">AT+VIT?</A></H3>
<OL>
DCE will return current Inactive Timer, followed by the OK result
code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VIT=?">AT+VIT=?</A></H3>
<OL>
DCE will return permitted interval of Inactive Timer.
<P>
The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>Note: This does comply with IS-101</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VLS=">AT+VLS=<I>device</I></A></H3>
<OL>
This command causes the DCE to select a voice I/O device.
<P>
The permitted values of <I>device</I> are:
<PRE>
0: disconnect all I/O devices
2: Telco line
8: External Microphone (Connect a Mic to dial-up line RJ-11 jack)
16: Internal Speaker
</PRE>
DCE Result codes:
<PRE>
OK : if DCE accepts this command.
ERROR: if <I>device</I> is not permitted.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VLS?">AT+VLS?</A></H3>
<OL>
DCE will return current I/O device followed by the OK
result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VLS=?">AT+VLS=?</A></H3>
<OL>
DCE will return permitted I/O devices. The response is:
<PRE>
0,2,8,16
OK
</PRE>
with <CR><LF> between each line.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VNH=">AT+VNH=<I>value</I></A></H3>
<OL>
This command causes the DCE to disable or enable automatic hang-ups
to a varying degree in the DATA and FAX modes.
<P>
The range of the <I>value</I> is from 0 to 2.
<P>
<I>value</I> = 0 (Default),
<OL>the DCE shall not disable automatic hang-ups.</OL>
<P>
<I>value</I> = 1,
<OL>the DCE shall disable automatic hang-ups. This behavior
shall persist until the DTE issues ATH, ATZ, or AT+VIP
command, or DTR drop.
The DCE shall perform on hook on a ATH command.</OL>
<P>
<I>value</I> = 2,
<OL>the DCE shall disable automatic hang-ups. This behavior
shall persist until the DTE issues ATH, ATZ, or AT+VIP
command, or DTR drop.
The DCE shall not perform on hook on a ATH command. </OL>
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <I>value</I> parameter
is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VNH?">AT+VNH?</A></H3>
<OL>
DCE will return current hang up mode, followed by the OK result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VNH=?">AT+VNH=?</A></H3>
<OL>
DCE will return permitted values of hangup mode. The response is:
<PRE>
0-2
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>NOTE: This does comply with IS-101</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VRA=">AT+VRA=<I>value</I></A></H3>
<OL>
This command sets the amount of time the DCE shall wait between
ringbacks before the DCE can assume that the remote station
has gone off hook. The default value is 70 (7 seconds).
<P>
The range of the <I>value</I> is from 0 to 255. The units are 0.1
second. A value of zero forces the DCE to return VCON immediately
after the ATD command is received.
<P>
DCE Result codes:
<PRE>
OK: if DCE accepts this command.
ERROR: if <I>value</I> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VRA?">AT+VRA?</A></H3>
<OL>
DCE will return current Ringback Goes Away Timer, followed by the
OK result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VRA=?">AT+VRA=?</A></H3>
<OL>
DCE will return the permitted interval of Ringback Goes Away
Timer. The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>
Note: This does comply with IS-101 except that ZyXEL default value
is set at 70. We derived this value after conducting numerous
tests and found it to be ideal with majority of the phone
systems.
</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VRN=">AT+VRN=<I>value</I></A></H3>
<OL>
This command sets the amount of time the DCE will wait looking for
Ringback. If the DCE does not detect a Ringback in this time period,
the DCE shall assume that the remote station has gone off hook.
<P>
The range of the <I>value</I> is from 0 to 255. The units are 0.1 second.
A value of zero forces the DCE to return VCON immediately after the
ATD command is received.
<P>
DCE Result codes:
<PRE>
OK : if DCE accepts this command.
ERROR: if <value> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VRN?">AT+VRN?</A></H3>
<OL>
DCE will return current Ringback Never Appeared Timer, followed by
the OK result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VRN=?">AT+VRN=?</A></H3>
<OL>
DCE will return the permitted interval of Ringback Never Appeared
Timer. The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>
Note: This does comply with IS-101 except that ZyXEL default value is set
to 57. Once again we derived this value from numerous tests that were
conducted on different phone systems.
</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VRX">AT+VRX</A></H3>
<OL>
This command causes the DCE to start the voice reception process.
<P>
The DCE begins the voice receive mode by returning the CONNECT result
code to the DTE. After this report, the DCE sends <DLE> shielded
Voice data to the DTE.
<P>
The DTE stops the voice receive state by sending a character other
than <XON> and <XOFF>. On termination of the voice receive state,
the DCE will append a <DLE><ETX> character pair, followed by the
VCON result code.
<P>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSD=">AT+VSD=<I>sds</I>,<I>sdi</I></A></H3>
<OL>
This command causes the DCE to set the silence detection sensitivity,
and the required period of silence before the DCE can report silence
detected at the end of a voice receive either with the QUIET or
SILENCE <DLE> shielded code.
<P>
See the description of the <DLE> shielded codes for the difference
between SILENCE and QUIET report.
<P>
The range of the sensitivity <I>sds</I> is from 0 to 31. Larger values
of this parameter imply that the DCE should treat noisier conditions
as silence. A value of zero disables the DCE silence detection; the
DCE shall not report QUIET or SILENCE <DLE> shielded codes.
<P>
The range of the interval <I>sdi</I> is 0-255 in units of 0.1 seconds.
<P>
DCE Result codes:
<PRE>
OK : if DCE accept this command.
ERROR: if <sds> or <sdi> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSD?">AT+VSD?</A></H3>
<OL>
This command causes the DCE to report the current <sds> and <sdi>
settings. The form of the response is:
<PRE>
<I>sds</I>,<I>sdi</I>
OK
</PRE>
with <CR><LF> between each line.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSD=?">AT+VSD=?</A></H3>
<OL>
This command causes the DCE to report the permitted ranges of <I>sds</I>
and <I>sdi</I>. The response is:
<PRE>
(0-31),(0,255)
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>
Note: It does comply with the IS-101 except for the default values.
Our default values are 15 for <sds> and 70 for <sdi>. These
default values were derived to work with the majority of the
phone systems found in the U.S. For example the reason we
increased the required silence period from 5 secs to 7 secs we
found that people tend to pause while leaving a message and it
could cause a false alarm by reporting DLE<s> or DLE<q> and
disconect a caller. On the other hand increasing it further
could cause the phone company to intervene and therefore
continue the recording.
</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSM=">AT+VSM=<I>cml</I></A></H3>
<OL>
This command causes the DCE to select a compression method as
follows:
<PRE>
<I>cml</I> = 1, 9.6 KBps CELP (Code Excited Linear Prediction)
<I>cml</I> = 2 (Default), 19.2 KBps 2-bit ADPCM
<I>cml</I> = 3, 28.8 KBps 3-bit ADPCM
<I>cml</I> = 30, 30.7kpbs new 3-bit ADPCM
<I>cml</I> = 4, 38.4Kbps 4 bit ADPCM
</PRE>
Note: Only PLUS enhanced models support CELP mode.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSM?">AT+VSM?</A></H3>
<OL>
This command causes the DCE to report the current compression
setting in the following form:
<PRE>
<I>cml</I>;<I>scs</I>;<I>vsr</I>
OK
</PRE>
with <CR><LF> between each line. Where:
<PRE>
<I>cml</I>: compression method label.
<I>scs</I>: silence compression sensitivity.
<I>vsr</I>: voice sampling rate.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSM=?">AT+VSM=?</A></H3>
<OL>
This command causes the DCE to report the compression methods
supported. The response is as follows:
<PRE>
1;CELP;1;0;(9600)
2;ADPCM;2;0;(9600)
3;ADPCM;3;0;(9600)
30;ADPCM;3;0;(9600)
4;ADPCM;4;0;(9600)
OK
</PRE>
with <CR><LF> between each line.
<P>
The first item in each line is the compression method label; the
second item is the compression scheme; the third item is number of
bits per sample; the fourth item is the silence detection threshold
level; the fifth item is the sampling rate.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSY=">AT+VSY=<I>value</I></A></H3>
<OL>
This command sets the DCE's voice recording re-sync timer.
<P>
The range of the <I>value</I> is from 0 to 255. The units are 50ms.
Default value is 1 (50ms).
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <I>value</I> is out of range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSY?">AT+VSY?</A></H3>
<OL>
DCE will return current re-sync timer, followed by the OK result
code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VSY=?">AT+VSY=?</A></H3>
<OL>
DCE will return permitted interval of Inactive Timer.
<P>
The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>
Note: Not defined in IS-101. This timer when set will allow the DTE
to send this resync code(<DLE><FS>) to signify the start of a
new voice data stream with the same parameters as the last
stream without first returning to the Voice Command State.
The IS-101 does mention about "Timing Marks" but does not
specify what interval you could set, nor a method of adjusting
it. This will give the user the flexibility to start a new voice
data stream at different points in the data stream.
</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VTS">AT+VTS=<I>string</I></A></H3>
<OL>
This command causes the DCE to produce DTMF and other tones.
<P>
The tone generation string consists of elements in a list with
each element separated by commas. Each element can be:
<P>
<OL>
<LI> A single ASCII character in the set 0-9, A-D, #, and *.
The DCE interprets the ASCII character as a DTMF digit with a
duration as specified by the AT+VBT command.
<LI> Three numbers separated by commas and enclosed in square
brackets. The DCE interprets the first and the second numbers
as the frequencies of the dual tones, and the third one as the
duration of the tone(s).
The frequency range is from 200 Hz to 3300 Hz; a frequency of
zero means silence. The range of the duration is 0-255 with
units of 0.1 seconds.
<LI> A single ASCII character and a number, separated by commas and
enclosed in curly braces. The DCE will interpret the ASCII
chracter as a DTMF digit, and the number as the duration of the
tone.
</OL>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VTS=?">AT+VTS=?</A></H3>
<OL>
This command causes the DCE to report the allowable tone string
elements. The response is as follows:
<PRE>
(0,200-3300),(0,200-3300),0-9,A-D,*,#
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>Note: Does comply with IS-101.</CITE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VTX">AT+VTX</A></H3>
<OL>
This command causes the DCE to start the voice transmission process.
<P>
The DCE begins the voice transmit mode by returning the CONNECT result
code to the DTE. After this report, the DCE accepts <DLE> shielded
Voice data from the DTE.
<P>
The DTE stops the voice transmit state by sending a <DLE><ETX>
character pair to the DCE. On termination of the voice transmit
state, the DCE will send the VCON result code.
<P>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VVT=">AT+VVT=<I>value</I></H3>
<OL>
This command causes the DCE to set the VCON response sensitivity,
a higher value will decrease the sensitivity of a VCON response.
The sole purpose of this command being added was to make it easier
for a user to detect an off-hook when going through a different phone
system or in some cases through a PBX. This accomplishes the same job
as +VRA and +VRN but a lot easier to derive.
<P>
The range of the <I>value</I> is from 0 to 255.
The default value is 16.
<P>
Result codes:
<PRE>
OK: The DCE issues this result code if DCE accepts this command.
ERROR: The DCE issues this result code if <I>value</I> parameter is out of
range.
</PRE>
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAME="AT+VVT?">AT+VVT?</A></H3>
<OL>
DCE will return current VCON sensitivity, followed by the OK
result code.
</OL>
<HR WIDTH=65% ALIGN=right>
<H3><A NAMe="AT+VVT=?">AT+VVT=?</A></H3>
<OL>
DCE will return permitted values of VCON sensitivity. The response is:
<PRE>
0-255
OK
</PRE>
with <CR><LF> between each line.
<P>
<CITE>Note: Not defined in the IS-101.</CITE>
</OL>
<P>
<A HREF="@HTMLPATH@/Modems/ZyXEL/codes.html"><IMG SRC="@HTMLPATH@/icons/next.gif"> DLE-shielded codes</A>.<BR>
<A HREF="@HTMLPATH@/Modems/ZyXEL/voice.html"><IMG SRC="@HTMLPATH@/icons/back.gif"> ZyXEL Advanced Voice Capability</A>.
<HR>
<ADDRESS>
<A HREF="@HTMLPATH@/sam.html">Sam Leffler</A> / <A HREF="mailto:sam@engr.sgi.com">sam@engr.sgi.com</A>.
Last updated $Date: 1998/10/12 20:47:51 $.
</ADDRESS>
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