CalAmp TTU-2830, Руководство по установке оборудования, Страница: 12 / 22

4.2.1 Size and Placement of LMU Unit
The dimensions of the LMU should be taken into account, particularly when installing in
a vehicle:
Whether you intend to place the LMU under a seat or into a cavity behind the vehicle’s
interior molded trim, be sure the LMU will fit before drilling any holes or running cable
•
Be certain that the cables running to the LMU will not be bent or constricted.
Damage to the cables may impede the LMU’s performance.
•
Be certain that the installation point will not violate any of the LMU’s
environmental specification (temperature, moisture, etc…) as improper
installation of the LMU may void the warranty.
Typical installations will place the LMU under the vehicle dash board, or in the trunk.
Make sure you can get access to the unit afterwards as under some circumstances it may
be necessary to add additional wiring or connections to the LMU.
4.2.2 Placement of Antennas
Placement of Combination and Internal Antennas
When dealing with combination antennas, it is more important to considered GPS
performance over Comm performance. GPS signal strengths are much lower than those
typically seen by cellular networks supported by the LMU. In order to maximize the
performance the LMU should have a clear view of the sky as possible. When installing
the GPS antenna in a vehicle, make sure that there are as few obstructions as possible
close to the LMU that might block the view 360° to the horizon. As with stand-alone
GPS antennas, nothing should not block the combination antenna beyond 5° above the
horizon with the best location being near the center of the roof. For more covert installs,
directly under the front or rear-windshields are also acceptable.
Examples of Good (Green), OK(Yellow) and Poor(Red) combo antenna placements