User's Manual

FP300RA User Manual
2140-72018-00-0A REV: A Page 17 Of 38
2.3.2.1 Antenna Mounting Position Requirements
FP-300RA antennas are mounted in accordance with the application requirements and antenna
manufacturer's instructions. Consider the following position requirements:
• Height: for above-the-lane installation, the antennas can be mounted on a gantry,
overpass, or other above-the-lane facility. Each antenna must be mounted at a
sufficient height to meet local vertical clearance requirements.
Any antenna can be damaged and/or misaligned if struck. If snow buildup on vehicles is
possible, mounting height must include clearance for snow buildup for the highest
anticipated vehicle using the lane(s).
• Multilane applications: each antenna should be mounted over the center of its
lane. For lane discrimination, antennas should be mounted over the center of the
highway or group of lanes to be included in the FP-300RA communication zone.
• Beside-the-road installation: the antenna(s) can be pole mounted.
Antennas must be mechanically positioned to provide the appropriate beam orientation for the
communication zone wanted. Suitable arrangements must be provided to permit mechanical
adjustment of antenna direction, to achieve the beam pattern and communication zone wanted.
2.3.2.2 FP-300RA-to-Antenna Cabling
The maximum distance between the FP-300RA and its antenna is limited by cable signal loss.
Generally, the total signal loss between the antenna and the FP-300RA must be less than 3 dB.
Any losses on antenna patch panels or switching matrices must also be taken into
consideration.
For installations where the FP-300RA-to-antenna cable length is less than 125 feet (38 meters),
you may use Times LMR 600/400, Andrew type LD F4-50A 1/2-inch Heliax, or other cables
with similar or better characteristics.
Cable routes should be carefully planned, to ensure they follow the shortest path yet are far
from sources of strong electrical interference such as electrical motors, air conditioning
equipment, two-way radios, etc. Make sure that cables are physically protected, for example,
by routing them within cable ducts: sharp bends, distortion of the cable outer shield, etc., may
increase the attenuation by an unpredictable amount.
2.3.3 Communication Cables
The cables connecting the FP-300RA communication ports (auxiliary, maintenance and in
particular the connection to the host computer) must be shielded. Communication-grade cables
consisting of twisted pairs with external shield should be used, and the shield must be
grounded at one end.
Cables should be run through grounded conduits, to minimize external interference.