2 the modem keep rebooting all the time, 3 no connection with modem through serial link, 4 receiving “no carrier” message – Robustel M1000 MP User Guide User Manual
Page 40: The modem keep rebooting all the time, No connection with modem through serial link, Receiving “no carrier” message
Robustel GoRugged M1000 MP User Guide
RT_UG_M1000 MP_v.1.0.0
20.12.2013
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4.2.2 The modem keep rebooting all the time:
Please make sure you have inserted the SIM card.
4.2.3 No connection with modem through serial link
Check if the serial cable has been connected properly.
Check if the serial cable has been made by following pin assignment given in section 2.6 PIN assignmen for
RS232.
Check if your program has proper setting. Factory setting of the modem is 115200,8,n,1.
Check if there is another program interfering with the communication program, such as conflict on
communication port access.
4.2.4 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 2.5
“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