User's Manual

4. HINTS FOR INTEGRATING THE MODEM

LZT 123 7468 P1A

Minimize the use of extension cables, connectors and adapters. Each

additional cable, connector or adapter causes a loss of signal power.

4.3.5 Possible Communication Disturbances

Possible communication disturbances include the following:

• Noise can be caused by electronic devices and radio transmitters.

• Path-loss occurs as the strength of the received signal steadily

decreases in proportion to the distance from the transmitter.

• Shadowing is a form of environmental attenuation of radio signals

caused by hills, buildings, trees or even vehicles. This can be a

particular problem inside buildings, especially if the walls are thick

and reinforced.

• Multi-path fading is a sudden decrease or increase in the signal

strength. This is the result of interference caused when direct and

reflected signals reach the antenna simultaneously. Surfaces such as

buildings, streets, vehicles, etc., can reflect signals.

• Hand-over occurs as you move from one cell to another in the GSM

network. Your mobile application call is transferred from one cell to

the next. Hand-over can briefly interfere with communication and

may cause a delay, or at worst, a disruption.

4.4 Attachments

The GM28 has been FCC certified using a number of attachments

including:

1. AC-DC Power Adaptor with Customized DC Lead

(Model # AD-0901000BS)

Input 230Va.c., 50Hz, 2m mains lead

Output: 9Vd.c. 1A, 2m d.c. lead with RJ11 connector. CE marked.

2. Tri-band GSM Antenna (GSM/PCN/1.9GHz)

(Model # DG300-FME/F)

Covert fit spider patch antenna, self-adhesive pad, 0dBi, 2m RG174

cable with FME female connector.

3. RS232 9-way Serial Cable

(Model # C-E-RS232-2M)

2m, 9-way cable, DB9 (female) to DB9 (male) connectors.