Technical information

Chapter 2: Hardware Interface Description
November 15, 2008 G24-L Module Hardware Description 21
Real Time Clock
G24-L incorporates a Real Time Clock (RTC) mechanism that performs many internal functions,
one of which is keeping time. The RTC subsystem is embedded in the PMIC and operates in all of
the G24-L operating modes (Off, Idle, Sleep), as long as power is supplied above the minimum
operating level.
The G24-L time and date can be set using the following methods:
• Automatically retrieved from the GSM network.
In case G24-L is operated in a GSM network that supports automatic time zone updating, it
will update the RTC with the local time and date upon connection to the network. The RTC
will continue to keep the time from that point.
• Using the AT+CCLK command.
Setting the time and date manually by this AT commands overrides the automatic network
update.
Once the time and date are manually updated, the RTC timer will keep the time and date
synchronized regardless of the G24-L operating state.
When the power supply is disconnected from G24-L, the RTC timer will reset and the current
time and date will be lost. On the next G24-L power-up the time and date will need to be set again
automatically or manually.