Applicant: Motorola, INC
2.5 Real Time Clock
The module incorporates a Real Time Clock (RTC) mechanism that performs many internal functions,
one of which is keeping time and alarm operation. The RTC subsystem is embedded in the module and
operates in all the different operating modes (Off, Idle, Sleep), as long as power is supplied above the
minimum operating level.
The module time and date can be set by the following methods:
Automatically retrieved from the network.
In case the module is operated in a 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 module operating state.
When the power supply is disconnected from the module, the RTC timer will reset and the current time
and date will be lost. On the next module power-up the time and date will need to be set again
automatically or manually
Motorola General Business Use
Page 16 of 36
FCC ID: IHDP56JE1
C24 Hardware Interface Manual