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If using ATA-only version (10-40xy-008) of the Encompass 4 Reader, use
continuous wave frequencies. These are 902.25 – 903.75 MHz and
910.00 – 921.50 MHz.
NOTE:
The Encompass 4 Reader’s #642NN command, Set RF Operating
Frequency can be used where backward compatibility with Encompass 2 or
AI1620 Readers is necessary. The #642NN command sets RF in 0.5 MHz steps.
Common Problems – Potential “Gotchas”
Frequency interference between readers
Frequency interference may be caused by incorrect spacing and angle of readers,
incorrect frequency assignment, objects or changes in the environment, incorrect
RF power settings, etc. See pages 2, 3, and 4.
Communications problems between the reader and backend host
These problems may be caused by incorrectly wiring the communications cable,
using the wrong cable, having a too-long cable run, or incorrectly setting
communications parameters between host and reader. See pages 5, 6, and 7.
Cable run for RS– 232 exceeds 50 feet in length
Fifty feet exceeds the
maximum length for RS– 232 interface
.
The interface should
be converted to RS– 422, wireless modem, fiber optic, or Wiegand. If in a noisy
environment or running long cable lengths, you may need to reduce the baud rate.
Long RF cable runs to antennas
For the external antenna-series Encompass 4 Readers, long RF cable runs
between the reader and the antenna may cause signal degradation or loss. This
scenario may be site-specific, but TransCore recommends limiting antenna cable
runs to 35 feet.
RF is not on
The technician must verify that RF is on by presence or on continuously.
Command #527 may be used to verify RF status. See page 14.
Improper grounding
Cable shielding should be connected to Earth Ground to prevent damage
from lightning or power surges.
Mixed tag population
In a mixed tag population, multiple tags in the same vehicle must be separated by
at least 2 inches, preferably a greater distance.
Reader not programmed correctly
The technician must verify that all parameters are set appropriately for the reader
location. Command #527 may be used to verify reader parameters. If tags are
Wiegand, the technician can use commands #532 and #533 to verify Wiegand
status.
Readers pointed toward each other
Readers must not be “aimed” directly facing each other or be in close proximity
back-to-back. See pages 1 through 4.
Tag presentation
Tags must be properly mounted in a location determined by the reader placement.
See page 2.
