> 3.3 | Operating Modes

> The table below briefly summarizes the various operating modes referred to in the following chapters.

> Table 7: | Overview of operating modes

> Normal operation | GSM / GPRS SLEEP | Various power save modes set with AT+CFUN command. Software is active to minimum extent. If the Terminal was registered to the GSM network in IDLE mode, it is registered and paging with the BTS in SLEEP mode, too. Power saving can be chosen at different levels: The NON-CYCLIC SLEEP mode (AT+CFUN=0) disables the AT interface. The CYCLIC SLEEP modes AT+CFUN=7 and 9 alternatingly activate and deactivate the AT interfaces to allow permanent access to all AT commands.
> GSM IDLE | Software is active. Once registered to the GSM network paging with BTS is carried out. The Terminal is ready to send and receive.
> GSM TALK | Connection between two subscribers is in progress. Power consumption depends on network coverage individual settings, such as DTX off/on, FR/EFR/HR, hopping sequences, antenna.
> GPRS IDLE | Terminal is ready for GPRS data transfer, but no data is currently sent or received. Power consumption depends on network settings and GPRS configuration (e.g. multislot settings).
> GPRS DATA | GPRS data transfer in progress. Power consumption depends on network settings (e.g. power control level), uplink / downlink data rates, GPRS configuration (e.g. used multislot settings) and reduction of maximum output power.
> POWER DOWN | Normal shutdown after sending the AT^SMSO command, after pressing the ON/OFF key or after the activation of the ONOFF line. The RTC works continuously, but the software is not active. Interfaces are not accessible.
> Airplane mode | Airplane mode shuts down the radio part of the module, causes the Terminal to log off from the GSM/GPRS network and disables all AT commands whose execution requires a radio connection. Airplane mode can be controlled by using the AT commands AT^SCFG and AT+CALA: With AT^SCFG=MEopMode/Airplane/OnStart the Terminal can be configured to enter the Airplane mode each time when switched on or reset. The parameter AT^SCFG=MEopMode/Airplane can be used to switch back and forth between Normal mode and Airplane mode any time during operation. Setting an alarm time with AT+CALA followed by AT^SMSO wakes the module up into Airplane mode at the scheduled time.