CC864-DUAL Hardware User Guide
1vv0300791 Rev 4.4 – 2011-01-26
Reproduction forbidden without Telit Communications S.p.A’s. written authorization - All Rights Reserved.
Page 54 of 63
3.14.2. VRTC
The VRTC pin brings out the real time clock supply, which is separated from the rest
of the module’s internal power supply, allowing the RTC to operate when all the other
module functionality is turned off.
A coin cell or backup capacitor can be added to this pin. However, a backup
capacitor does not support the RTC feature. The coin cell or backup capacitor is
charged when the module is on, and supplies power to the RTC circuit when the
module is turned off.
WARNING
: NO devices must be powered from this pin.
3.14.3.
STAT_LED – Network Status LED
This pin is an open collector output signal with an internal pull-up resistor.
The STAT_LED pin shows information on the network service availability and call
status.
The STAT_LED pin usually needs an external transistor to drive an external LED.
Therefore, the status indicated in the following table is reversed with respect to the
pin status:
LED status
Device Status
Permanently off
Device off
Fast blinking(Period 1s, Ton 0.5s)
Net search/Not registered/Turning off
Slow blinking(Period 3s, Ton 0.3s)
Registered full service
Permanently on
A call is active