Fine-Tuning and Verifying the Read Zone
If the read zone is too wide or too deep for your application, it can be fine-tuned by physically adjusting
the Encompass 4 Reader or external antenna mounting orientation, reprogramming the actual RF power
output (
#644NN Set RF Attenuation
), and/ or reprogramming the RF sensitivity range (
#643NN
Set ATA Operating Range
and
#6
45NN Set eGo and eGo Plus Operating Range
). The
combination of these adjustments allows you to confine the read zone to the area where tagged vehicles
pass. This operation also minimizes reading unwanted vehicles in adjacent lanes or parking areas.
See sections
“643NN Select ATA Operating Range (Distance)” on page 7–120, “645NN Set eGo and eGo
Plus Operating Range (Distance)” on page 7–121
,
and
“644NN Set RF Attenuation” on page 7–120
for
more information.
Note:
As described in
“Marking the Read Zone” on page 4-63
, marking the read pattern using test
tags that are not mounted to vehicles give a general idea of the read pattern but the pattern will
vary somewhat when actual vehicles with tags are tested. Final adjustments must be made with tags
properly mounted on a variety of vehicles.
Physically Orienting the Encompass 4 Reader
You can manually adjust the location of the read zone by loosening the Encompass 4 Reader mounting
brackets and pointing the reader in the desired direction. The unit should be aligned to point directly at
the tag as it enters the desired read zone.
Physically Orienting the Encompass 4 Reader Antenna
You can manually adjust the location of the read zone by loosening the antenna mounting brackets and
pointing the antenna in the desired direction. The unit should be aligned to point directly at the tag as it
enters the desired read zone.
Fine-Tuning the Read Zone by Lowering Output Power
You can make the read zone smaller by adjusting the Encompass 4 Reader RF power output from a
maximum of 2 watts to a minimum of 200 milliwatts using command
#644NN Set RF Attenuation
.
Lowering the RF power has the added benefit of reducing RF interference with adjacent lanes.
To adjust the read zone by lowering output power
1. Ensure that your PC is communicating with the Encompass 4 Reader using a terminal emulation
program as described in the section
“Verifying Communications” on page 8–136
.
2. Mark the current read zone as described in section
“Marking the Read Zone” on page 4-63
Caution
Test tags should be compatible with your Encompass 4 Reader. Test tags can be ATA-protocol,
ISO-compliant, or Inter-Agency Group tags affixed to a plastic or wooden yardstick, or eGo
or eGo Plus sticker-type tags affixed to a piece of nonmetallic windshield-type glass 0.190 to
0.230 in (4.82 to 5.84 mm) in thickness. The sticker-type tags have a reduced read range when
not attached to glass.
3. Enter command
#01
to switch to command mode. You are prompted with
#DONE
from the reader and
can now enter reader commands.
Encompass 4 Reader System Guide
TransCore Proprietary.
8–146
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