User guide

EG_GenPro30e_1006_UG_002_UK Page 22 / 37
Descriptions and non-contractual illustrations in this document are given as an indication only.
ERCO&GENER reserves the right to make any modifications.
5.4 Checking the quality of the GSM reception signal
To know the reception level, the GenPro 30e must absolutely have its activated SIM card inserted.
The modem will be able to make a call only if the received GSM signal is sufficient.
The command AT+CSQ allows to know the reception level (rssi) of the signal sent by the closest GSM Base
Transceiver Station (BTS), as well as the receive bit error rate (ber).
When the SIM card is inserted and the PIN code entered, the command AT+CSQ lows to measure the signal
from the BTS of the subscribed operator network.
This command can also be used without the SIM card, it indicates in this case he nearest BTS which can be
ORANGE, SFR or BOUYGUES for France (Without the SIM card, the device does not recognize the current
subscription). It is therefore advisable to do the measure when the SIM card is present.
To check the quality of the GSM signal, do the following operations:
With a communication software like Hyperterminal, enter the command AT+CSQ.
The response is in the following format:
+CSQ : <rssi>, <ber> with :
<rssi> = indicates the reception level,
<ber> = receive bit error rate.
Check the answered value <rssi> with the help of the table hereunder.
The GSM modem works normally with a minimum <rssi> between 11 and 15.
Bellow 10, the signal level is insufficient; the modem cannot work depending on the geographical situation or
the vehicle mobility. Above 15, the signal is sufficient.
For more information about AT commands, see the "Commands List" document of ERCO & GENER.
<rssi> value
Gain (dbm) Interpretation <ber> value Interpretation
0 -113 dbm Insufficient 0 to 7
See ETSI GSM 05.08
standards
1 to 10 -111 to -95 dbm Insufficient
11 to 30 -93 to -53 dbm Sufficient
31 (max) -51dbm Perfect
99 Unknown/not detectable 99 Unknown/not detectable