MD 5850
Installation Manual
2.2 Installation site
2.2.1 Toll plaza superstructure
The normal configuration at toll plaza with separate lanes, is to have the MR installed hanging
from the toll plaza superstructure. Mounting the MR under the superstructure also provides
protection from rain, snow, sun heat radiation etc.
In some cases, a gantry or pole will be more suitable for mounting the MR, but then there is no
protection from, rain, snow, sun heat radiation etc.
2.3 Basic installation
2.3.1 Mounting height and angle
The normal mounting height is 5.5 to 6m above the road, and the normal mounting angle is 45
°
down from vertical (fig.2.3.1). Optimum performance is obtained when the MultiReader (MR)
is mounted above the middle of the lane.
If the centre of the antenna lobe must correspond with the centre of a magnetic loop, it is
preferred that magnetic loop is installed in a position, which gives a normal MultiReader angle.
In vehicle access control systems with physical barrier where the magnetic loop vehicle
detection and OBU transactions has to be matched, the optimum-mounting angle could be
between 25
°
and 45
°
relative to the vertical plane through the MR. It is not recommended to
have a mounting angle (pointing angle) below 25
°
because then it is possible that overhanging
roof of special vehicles could shadow the tag.
An angle below 45
°
will reduce the communication zone length. This must be considered when
the vehicles are passing at a high speed.
5.5-6.0m above lane surface
45
°
Figure 2.3.1 Side view of MR mounted hanging from concrete superstructure
Q-Free
®
ASA
645-054-1999 rev.4
5 of 20
