User's Manual

GM29 INTEGRATOR’S MANUAL
40
LZT 123 7361 R1A
Signal Strength
The modem has to be placed in a way that ensures sufficient signal
strength. To improve signal strength, the antenna can be moved to
another position. Signal strength may depend on how close the modem
is to a radio base station. You must ensure that the location at which you
intend to use the modem, is within the network coverage area.
Degradation in signal strength can be the result of a disturbance from
another source, for example an electronic device in the immediate
vicinity. More information about possible communication disturbances
can be found in section 4.3.5, page 42.
When an application is completed, you can verify signal strength by
issuing the AT command AT+CSQ. See “AT+CSQ Signal Strength”,
page 89.
Tip! Before installing the modem, use an ordinary mobile telephone to check
a possible location for it. In determining the location for the modem and
antenna, you should consider signal strength as well as cable length
Connection of Components to GM29
The integrator is responsible for the final integrated system. Incorrectly
designed or installed, external components may cause radiation limits to
be exceeded. For instance, improperly made connections or improperly
installed antennas can disturb the network and lead to malfunctions in
the modem or equipment.
Network and Subscription
• Before your application is used, you must ensure that your chosen
network provides the necessary telecommunication services.
Contact your service provider to obtain the necessary information.
• If you intend to use SMS in the application, ensure this is included in
your (voice) subscription.
• Consider the choice of the supplementary services described in
section “2.4.2 Short Message Service”, page 17.
4.2.2 How to Install the Modem
Power Supply
• Use a high-quality power supply cable with low resistance. This
ensures that the voltages at the connector pins are within the allowed
range, even during the maximum peak current.
• When the unit is powered from a battery or a high current supply,
connect a fast 1.25A fuse in line with the positive supply. This
protects the power cabling and modem.