TransCore encompass 4 - Table 1 Examples of Staggered Reader Frequencies

• RF output attenuation
• Range discrimination setting
• Other sources of interference and reflection
The Encompass 4 Reader must be positioned to allow the RF signal to travel to and return from the tags
within the designated range and be placed in an area where it is not likely to be bumped out of alignment. If
the antenna becomes misaligned or some nearby structure is added or removed, system operation can be
seriously aected.
The external antenna must be positioned to allow the RF signal to travel to and return from the tags within
the designated range and be placed in an area where it is not likely to be bumped out of alignment. If the
antenna becomes misaligned or some nearby structure is added or removed, system operation can be
seriously aected.
For instructions on setting the read zone, refer to “Fine-Tuning and Verifying the Read Zone” on page
8–146.
Other Encompass 4 Readers in the Area
Sites with more than one Encompass 4 Reader in proximity should have them configured with a frequency
separation of at least 2 MHz from adjacent readers. If more than one Encompass 4 Reader and antenna
is in a side-by-side or multiple lane application, the frequencies should be staggered. Also, Encompass 4
Readers may not operate accurately if they directly face each other or are positioned back-to-back.
Table 1 shows examples of staggered reader frequencies in a site with up to 14 readers.
Table 1 Examples of Staggered Reader Frequencies
Lane Number Reader Frequency Lane Number Reader Frequency
1 912.5 2 915
3 917.5 4 913.5
5 916 6 918.5
7 914.5 8 917
9 913 10 915.5
11 918 12 914
13 916.5 14 919
Lane Configurations
TransCore recommends that trac be guided through a controlled lane to consistently obtain accurate tag
readings and to prevent physical damage to the Encompass 4 Reader. The following subsections describe
some common lane configurations and oer suggestions for positioning the Encompass 4 Reader within the
controlled trac flow.
Chapter 2 Developing the Site Plan
TransCore Proprietary
2–11