4.2 Operational status of the modem
The operational status of the modem is given by the LED light located on the front panel of
the modem. The table below gives the meaning of the various statuses available.
Table 10
: Operational status of the modem
LED Status
LED light activity
Modem status
LED ON permanent
Modem is switched on
Not registered on the network
LED Flashing slowly
Idle mode
Connected to the network
ON
LED Flashing rapidly
Transmission mode
OFF
LED OFF
Modem is switched off
4.3 Verifying the received signal strength
The modem establishes a call only if the received signal is sufficiently strong. To verify
the received signal strength, do the following:
Using a communication software such as HyperTerminal program, enter the AT command
AT+CSQ. Value appears for the received signal strength.
Verify the result with the values given in the table below.
Table 11
: Values of received signal strength
Value of received signal strength
(AT+CSQ response)
Interpretation of the
received signal strength
0 - 10
Insufficient(*)
11 - 31
Sufficient(*)
Greater than 99
Insufficient(*)
(*) Based on general observations.
4.4 Verifying the network registration of the modem
1. Make sure a valid SIM card has been previously inserted in the SIM card holder of the
modem.
2. Using a communication software such as HyperTerminal program, enter the following
AT command: AT+CREG?. Value appears as a response.
3. Verify the result with the values given in the table below.
Table 12
: Values of network registration
Value(*)
Network registration
0,1
Yes
0,5
Yes (registered roaming)
(*) refer to AT commands documentation [1] for further information about the other
returned values and their meaning.
If the modem is not registered, perform the following procedure:
¾
Check the connection between the modem and the antenna.
¾
Verify the signal strength to determine the strength of the received signal (refer to
www.logicbus.com
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