24
NOTICE
Enabling low power mode as described herein also deactivates the RS232 transceiver!
5.4.2
Disabling the low power mode by user
•
Set the DTR control line from Low to High.
•
Low-power mode should be exited automatically. After setting DTR from Low to High, the module
doesn’t save power, but the module is saving power again after setting DTR from High to Low.
•
The RS232 transceiver is activated immediately.
•
AT channel is available immediately after changing DTR from Low to High.
•
Send AT command “AT+CFUN=1” to remain in normal mode.
5.4.3
Disabling the low power mode upon receiving GSM activity
•
Pre-requisite: the RING line must be connected between DTE and DCE for this function to work.
The RING pin is used to indicate incoming SMS or calls.
•
The DTR control line is still at a low level.
•
GSM module is called or receives an SMS.
•
Low-power mode should be exited automatically, if calling or sending an SMS to the GSM module.
NOTICE
The user must set DTR line to high in order to activate the RS232 transceiver, this is not done
automatically.
5.5
Operating states / green LED
The modem has a green power up LED, as depicted below, which is used to indicate various operating
states. These states are described in following table.
Default setting:
•
Set alternate Timings: at#sled=4
•
Safe configuration: at#sledsav
SLED = 2,50 Operating state of GT910 G
Terminal
green LED state
Device off
Permanently off
Net search / not registered
Fast blinking (period=1s, LED
on
=0,5s)
Registered full service
Slow blinking (period=3s, LED
on
=0,3s)
Low power mode activated
Permanently off
Table 7: Operating states of the green LED
5.6
Current consumption Measurements
The following table shows the typical power consumption of the Terminal in different modes.
