Specifications

Smart Machine Smart Decision
SIM900_AT Commands Manual_V1.07 158 2012.12.10
frequency=3.25/(period+1), for example, if <period> is set to 100, we
get a frequency: 3.25/101=32.178Khz.
z The equation of <level> and duty factor is: duty factor=(level+1).
6.2.47 AT+ECHO Echo Cancellation Control
AT+ECHO Echo Cancellation Control
Response
+ECHO: MIC:(list of supported <mic>s), ES:(list of supported <es>s),
SES:(list of supported <ses>s), MODE:(list of supported <mode>s)
OK
Test Command
AT+ECHO=?
Parameters
See Write Command
Response
+ECHO: (<mic0>,<es0>,<ses0>,<mode0>)...,
(<micn>,<esn>,<sesn>,<moden>)
OK
Read Command
AT+ECHO?
Parameters
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+ECHO=<mi
c>,<es>[,<ses>[,<
mode>]]
Parameters
<mic> Audio channel
0 Main audio handset channel
1 Aux audio headset channel
2 Main audio handfree channel
3 Aux audio handfree channel
<es> Echo suppression
0-8 (when mic=0or1 default value is 0; when mic=2 or 3 default
value is 7) the bigger the value, the stronger the restraint.
<ses> Selective echo suppression
0-6 (when mic=0 or1 default value is 0; when mic=2 or 3 default
value is 5)
<mode> 0 Close echo algorithm
1 Open echo algorithm
Reference Note
z Please refer to actual model for channel number.