TransCore 05531 User Manual
Developing the Site Plan
2-19
Figure 2-8 Overhead Installation
Reflection, Refraction, and Diffraction of RF
Signals
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/
4800 Multiprotocol 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.
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/
4800 Multiprotocol 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 par-
tially reflected by nonconducting materials such as dirt, wood, ice, asphalt, and con-
crete. When nonconducting materials in the system environment become wet, they
increase reflection of RF signals.
tially reflected by nonconducting materials such as dirt, wood, ice, asphalt, and con-
crete. When nonconducting materials in the system environment become wet, they
increase reflection of RF signals.
The Encompass 4/4800 Multiprotocol Reader and/or antenna mounting location, aim-
ing, and range control adjustment, and use of presence detectors can reduce interfer-
ence 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. See Chapter
ing, and range control adjustment, and use of presence detectors can reduce interfer-
ence 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. See Chapter
mation.