TransCore 0596465PT15 Manuel D’Utilisation

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Encompass 4H Reader System Guide
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If the Encompass 4H Reader is installed in an overhead location, optimal tag position 
is in the top center of the windshield in the area behind the rear view mirror or on the 
vehicle’s front license plate or center bumper as illustrated in 
.
Figure 2-5  Typical Tag Positions Used with Overhead Reader
Note:  Metallized coatings on some vehicle windshields and windows shield the RF 
energy emitted by the Encompass 4H Reader and may cause tags to be misread. Many 
metallized windshields have areas that are not metallized in which the tag can be 
placed and reasonable results achieved. If there are no openings in the metallized 
coating in which to install an interior tag, install exterior-type tags on the exterior of 
the vehicle.
Refer to Chapter 
for more 
detailed information on tag positioning.
Site Layout and Traffic Flow
The following site layout and traffic flow considerations are critical when determining 
Encompass 4H Reader installation locations:
The Encompass 4H Reader read zone
Other Encompass 4H Reader units in the area
Lane configurations
Reflection, refraction, and diffraction of RF signals 
Existing signal interference at the site