User's Manual

4. HINTS FOR INTEGRATING THE MODEM

LZT 123 7468 P1A

• When the SIM card hatch is opened, the SIM card connectors lie

exposed under the SIM card holder. CAUTION: Do not touch these

connectors! If you do, you may release an electrical discharge that

could damage the modem or the SIM card.

• When designing your application, the SIM card’s accessibility

should be taken into account. We always recommend that you have

the SIM card protected by a PIN code. This will ensure that the SIM

card cannot be used by an unauthorized person.

4.1.3 Antenna

• If the antenna is to be mounted outside, consider the risk of

lightning. Follow the instructions provided by the antenna

manufacturer.

• Never connect more than one modem to a single antenna. The

modem can be damaged by radio frequency energy from the

transmitter of another modem.

• Like any mobile station, the antenna of the modem emits radio

frequency energy. To avoid EMI (electromagnetic interference), you

must determine whether the application itself, or equipment in the

application’s proximity, needs further protection against radio

emission and the disturbances it might cause. Protection is secured

either by shielding the surrounding electronics or by moving the

antenna away from the electronics and the external signals cable.

• The modem and antenna may be damaged if either come into contact

with ground potentials other than the one in your application.

Beware, ground potential are not always what they appear to be.

• If the application containing the GM28 uses an antenna which is less

than 20cm away from any part of the user’s body, integrators are

legally obliged to publish SAR figures for the product. SAR testing

is the responsibility of the system integrator.

• Even if SAR measurements are not required it is considered good

practice to insert a warning in any manual produced, indicating it is a

radio product and that care should be taken.

• The GM28 module is FCC approved for fixed and mobile

applications. If the final product after integration is intended for

portable use, a new application and FCC ID is required.

4.2 Installation of the Modem

4.2.1 Where to Install the Modem

There are several conditions which need to be taken into consideration

when designing your application as they might affect the modem and its

function. They are: