Specifications

Chapter 18 – Hardware-Related Commands
Multi-Tech Systems, Inc. AT Commands for EDGE Modems (S000371B) 231
LED Behavior ME operating status if AT^SSYNC=1 ME operating status if AT^SSYNC=2
500 ms on / 25 ms off Packet switched data transfer in
progress.
Same as for AT^SSYNC=1
Permanently on Depending on type of call:
Voice call: Connected to remote party.
Data call: Connected to remote party or
exchange of parameters while setting
up or disconnecting a call.
This applies no matter whether the ME
works at full functionality level
AT+CFUN=1 or in one of the CYCLIC
SLEEP modes where it wakes up only
temporarily to make the call.
Same as for AT^SSYNC=1
n *600 ms on /n *600
ms off
Not possible: With AT^SSYNC=1, LED
signal is disabled in SLEEP mode.
SLEEP mode is activated (AT+CFUN
parameter <fun> ≠ 1), but the ME is
not registered to the GSM network
(e.g., SIM not inserted or PIN not
entered, and therefore, either no
network service or only Limited
Network Service is available.
n * 75 ms on / n * 3 ms
off
Not possible: With AT^SSYNC=1, LED
signalization is disabled in SLEEP
mode.
SLEEP mode is activated (AT+CFUN
parameter <fun> ≠ 1) while the ME is
registered to the GSM network.
n * 500 ms on / n * 25
ms off
Not possible: With AT^SSYNC=1, LED
signalization is disabled in SLEEP
mode.
SLEEP mode is activated (AT+CFUN
parameter <fun> ≠ 1) while the ME is
registered to the GSM network.
Additionally, PDP context is activated.
Note: When the ME is in Limited Service or IDLE mode with/without PDP context activated, the on/off time ratio
of the LED is always the same, no matter whether or not power saving is enabled. The only difference is that in
SLEEP mode the duration of the on/off periods is a multiple n of the equivalent periods without SLEEP mode.
The multiple n is synchronous to the active state of CTS during SLEEP mode (where CTS is set/reset every 0.9 -
2.7 seconds). See also AT+CFUN for the timing of CTS.