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4.3. Service Mode
The modem is configured in the service mode. The service mode is enabled automatically if both SIM trays
are ejected from the modem. If the modem has at least one tray available, it switches to the operating mode.
Data communication with a computer is carried out via USB interface in the service mode. In this case the
modem is recognized as a virtual COM port. The computer detects the modem as a virtual COM port.
You can configure the modem using the ATM Control configuration utility as well as using the AT commands
in any terminal program. The ATM Control utility is available for free download from the official website of the
Radiofid System Company
.
All AT commands, except passwords, are case-insensitive (
at$sim1? is equivalent to AT$SIM1?).
Any AT command must end with the <CR> new line character (the Enter key). If the entered command is incor-
rect, an error message is displayed in the log.
To enter the service mode, it is required to enter the corresponding password (default value
– 5492). Before
entering the password in the terminal application, only the query for the version and model of the device and
the IMEI module are available.
4.4. Offline Mode
In the offline mode the modem performs all its functions, except for connection to the network. In this case
the modem remains registered in the GSM network, supports calls and SMS messages, operation of the GPIO
pins, watchdog timers and switch to the primary SIM card. Offline mode provides economy of traffic and power
consumption. It is used if no continuous network connection is required.
Switch to the offline mode indicates disconnection; exit from the offline mode indicates setting up connection
(network access).
Switch to the offline mode can be implemented:
If the GPRS operation interval set in the settings is expired
On call
When recognizing the code word by the modem
When data is not transmitted within the set time interval
By SMS command
Exiting the offline mode:
By the specified exact time
By period
On call
