Robustel M1000 USB User Guide - Manual (Page 38)

Robustel GoRugged M1000 USB User Guide
RT_UG_M1000 USB_v.2.0.0
17.01.2014 37 / 39
Confidential
4.2.1 The modem’s LED does not light:
 Check if modem has connected to a proper power supply.
 Check if the power connector is properly inserted.
4.2.2 The modem keep rebooting all the time:
 Please make sure you have inserted the SIM card.
4.2.3 Receiving “No Carrier” Message
If the modem returns a “No Carrier” message upon an attempted call (voice or data), then refer to the table below
for possible causes and solutions.
If the modem returns…
Then ask… Action…
“No Carrier”
Is the received signal strong enough?
Use “AT+CSQ” to check RSSI, please check
Signal Strength Indication.
Is the antenna properly connected? Refer to section 错误!未找到引用源。
“No Carrier” (when trying to
issue a voice communication)
Is the semicolon (;) entered
immediately after the phone number
in the AT command?
Ensure that the semicolon (;) is entered
immediately after the phone number in the
AT command.
e.g. ATD123456;
“No Carrier” (when trying to
issue a data communication)
Is the SIM card configured for data /
fax calls? Configure the SIM card for data / fax calls
(Ask your network provider if necessary).
Is the selected bearer type supported
by the called party? Ensure that the selected bearer type is
supported by the called party.
Is the selected bearer type supported
by the network?
Ensure that the selected bearer type is
supported by the network.
If no success, try bearer select type by AT
command: AT+CBST=0,0,3
Signal Strength Indication
Value of received signal strength indication (RSSI)
Interpretation of the received signal strength
0 to 12 Insufficient or weak
13 to 19 Average
20 to 31 Good
99 No signal