User's Manual

4. HINTS FOR INTEGRATING THE MODEM
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LZT 123 7468 P1A
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.
Securing the modem
• Before securing the modem take into account the amount of
additional space required for the mating connectors and cables that
will be used in the application.
• Where access is restricted, it may be easier to connect all the cables
to the modem prior to securing it in the application.
• Securely attach the GM28 modem to the host application using two
3mm diameter pan-head screws of appropriate length as shown
below.
Caution! Do not exceed a torque of 25Ncm when tightening the fixings screws.
Excessive torque applied to the screws can crack the plastic case.
4.3 Antenna
4.3.1 General
The antenna is the component in your system that maintains the radio
link between the network and the modem. Since the antenna transmits
and receives electromagnetic energy, its efficient function will depend
on:
• the type of antenna (for example, circular or directional);
• the placement of the antenna;