Road Loop Antenna Installation
© 1999, AXCESS
TM
Inc.
750.001.003
Revised June 1999
61
Road Loop Layout & Connecting to the ATU
Step 1:
If used for gate access, position the Road Loop Antenna
far enough before the entrance to allow the gate to be fully
open by the time a vehicle reaches it. The gate will be
activated when the Tag is over the Road Loop.
Step 2:
If there is a safety loop for the gate, do not use the same
cut. Placing the Road Loop with the safety loop will change
the inductance of the Road Loop. If they are installed on
top of each other, there will be interference between them
and neither is likely to operate properly.
Reader
ATU
Dim
e
n
s
io
n
B
Dimension A
Dipole
Antenna
4 f
e
et
Max lead-in wire length:
20 feet
Max distance
between Dipole Antenna
and Road Loop Antenna:
20 feet.
Max cable length between Reader
and ATU: 80 feet
Minimum distance
between Dipole Antenna
and ground surface:
4 feet
Road Loop Antenna
¼ inch saw cut
direction of traffic
Slightly less than
width of the lane
Mounted on same
side as Tags
Figure 23 Road Loop Antenna installation diagram
Step 3:
Mark the outline of the antenna (yellow contractor’s
crayon, chalk, etc.). For neatness, ensure that the sides of
the loop rectangle are parallel or perpendicular to
surrounding buildings, fences, etc., as appropriate and
ensure that the corners are 90 degrees.
The long sides (Dimension A, Figure 23) will measure the
actual width of the antenna purchased (i.e., 14 feet, 20
feet, 26 feet, etc.) and be slightly shorter than the width of
the road.
IMPORTANT!
The short sides (Dimension B) of the road
loop antenna should
always
measure 4 feet.
Step 4:
If necessary, drive square concrete nails (or similar) into
the road surface at the corners to provide the proper