User guide

Developers guidelines | AT commands
48 June 2010
AT&C Circuit 109 (DCD) control
AT&D Circuit 108 (DTR) response
3 BUSY result code given if called line is busy. NO
DIALTONE result code is not given. Reports line
speed together with the CONNECT result code
4 BUSY result code given if called line is busy. NO
DIALTONE result code returned if no network.
Reports line speed together with CONNECT result
code. Default value
Description: Determines the behaviour of the carrier detect signal (CT109).
Set command: AT&C[=][<value>]
Read command: AT&C? Displays the current <value> setting.
Read command
response: &C: <value>
Test command: AT&C=? Shows if the command is supported.
Test command
response: &C: (list of supported <value>s)
Parameter:
<value>:
<value> Description
0 DCD always on
1 DCD follows the connection. Default value
Description: Controls how the DCE responds when the Data Terminal Ready (DTR)
signal (ct 108.2) is changed from on to off condition.
Set command: AT&D[=][<value>]
Read command: AT&D? Displays the current <value> setting.
Read command
response: &D: <value>
Test command: AT&D=? Shows if the command is supported.
Test command
response: &D: (list of supported <value>s)
Parameter:
<value>:
<value> Description
0 Ignore. Default value
1 When in online data mode: Switch to online
command mode. All other states: Disconnect and
switch to offline command mode
<n> Description