Lane Configurations Using an External Antenna
TransCore recommends that traffic be guided through a controlled lane to consistently obtain accurate tag
readings and to prevent physical damage to the Encompass 4 Reader and antenna.
Reflection, Refraction, and Diffraction of RF Signals
RF signals can be reflected, refracted, or diffracted by metal objects, walls, and even wet pavement or ice.
Any of these factors can alter or degrade system performance. When designing your site plan, you must
consider permanent structures and transient factors in the vicinity that may affect RF signals being generated
by the Encompass 4 Reader. Permanent structures include buildings, chain link fences, guard shacks, and
gates. Transient factors include passing traffic and local weather conditions, such as rain or snow. Symptoms
of reflection, refraction, and diffraction include reading tags that are out of the desired read zone or tags
being read from another lane.
The most common RF reflectors are metallic surfaces. RF signals may also be partially reflected by
nonconducting materials such as dirt, wood, ice, asphalt, and concrete. When nonconducting materials in
the system environment become wet, they increase reflection of RF signals.
The Encompass 4 Reader and/or antenna mounting location, aiming, and range control adjustment, and use
of presence detectors can reduce interference from RF reflections. When these actions cannot adequately
control reflections, other techniques such as shielding, absorbing, range sensitivity adjustment, or barriers
can also be used. Refer to
“Chapter 9 Troubleshooting and Maintenance” on page 9–149
for more
information.
Figure 9 Overhead Installation
Encompass 4 Reader System Guide
TransCore Proprietary.
2–14
Summary of Contents for encompass 4
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