User Manual

SARA-R4 series-AT commands manual
UBX-17003787 - R16
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1AT command settings
Page 12 of 401
To switch back to data mode from OLCM the O AT command is used. For more details, see also the &D AT
command.
When using the multiplexer and PPP combined, toggling the DTR line (of the physical serial interface where the
multiplexer protocol is started) from ON to OFF state does not terminate the PPP session and return the device
to the command mode. In this configuration, it is recommended that the host terminates the PPP session,
which can be done by sending LCP_TERM REQ or deasserting the DTR virtual line (sending of specific MUX
MSC command).
• SARA-R4 / SARA-N4 - For more details, see the SARA-R4 series application development guide [177]).
SARA-R4 / SARA-N4
The DTR transition is ignored if the DCE is in online command mode during a PPP call. To tear down the
PPP call, switch back to data mode by means of the O AT command and then toggle the DTR from ON
to OFF state.
1.1.2Command description
The AT commands configure and enable the cellular module functionalities according to 3GPP normative and
u-blox specifications. The AT commands are issued to the module via a hyper terminal through a command
line and are described in the following sections. A general description of each command is provided including
the functionalities, the correct syntax to be provided by the TE/DTE, the allowed responses and an example.
The command description defines each named parameter with its type, its range (valid / acceptable values),
the default value (when available) and the factory-programmed value (when applicable).
For default value it is intended the value automatically set if the parameter is omitted and at the module
power-on (if the command setting is not stored in NVM/profile). For factory-programmed value it is intended
the value set at the module power-on when the setting is not modified respect with the manufacturer setting;
it is valid for the commands that store the setting in NVM/profile.
The summary table on the top of each command section and the Appendix B lists all the u-blox cellular modules
that support that command.
The example provided in the command description refers only to the handling provided by the command.
It may be not valid for all the products which the document is applied to. The list of allowed values for a
specific product is provided in the corresponding "Defined values" section.
In this document <CR><LF> are intentionally omitted in the command syntax.
If a parameter is omitted, no value will be inserted between the two commas indicating the interested
parameter in the command line sent by the DTE.
1.1.3Default values
If the command parameters are optional, they can be left out in the command line. If not otherwise specified,
the default values are assumed as follows:
• For parameters of type Number, the default value is 0
• For parameters of type String, the default value is an empty string
1.1.4Command line
The AT commands are typically issued to the cellular modules using a command line with the following generic
syntax:
"AT"<command_name><string><S3_character>
Where:
• "AT": prefix to be set at the beginning of each command line
• <command_name>: command name string; it can have a "+" character as prefix
• <string>: string consisting of the parameters value following the syntax provided in this manual
The following rules are used when describing the command syntax:
o <...>: the name in angle brackets is a parameter. The brackets themselves do not appear in the command
line
o [...]: the square brackets represent the optional parameters of a command or an optional part of the DCE
information text response. Brackets themselves do not appear in the command line. When a parameter
is not given, the value will be set to the default value provided in the command description