LightPointe AireLink 60, Installation And User Manual

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AireLink

60 Installation and User Manual Rev. D System Installation
Page 66
7. Look through the Alignment Sight Tool and turn the Elevation and Azimuth Adjustment Screws
until the opposite antenna location shows in the middle of the Alignment Sight Tool. The inside
of the tool is reflective and this helps to center the remote antenna site location. In case the
opposite side is too far away to be clearly seen, please use binoculars to find an easy
recognizable landmark close to the opposite antenna side. Perform the same procedure at both
sides.
8. The alignment tool is meant to provide a rough alignment towards to opposite antenna location.
It is however not an exact tool for finding the best alignment of the antennas. More precise
alignment is done via the digital voltmeter or the
LightPointe BLE Tool that measures the receive
signal strength/RSSI voltage. Within several dB of accuracy the RSSI voltage reading in Volt
corresponds to the RF RSSI signal reading in dBm. In other words, and with the correct polarity
chosen, a system that is not aligned at all will show a negative voltage reading close to –0.80
Volt and this translates into -80 dBm. This signal level is far too low to establish a data
connection. During the alignment process the voltage reading will increase, meaning “less
negative” voltages or higher RF RSSI reading in dBm will be recorded. The goal is to align the
system at its best possible and highest RSSI reading (e.g. increase the voltage reading from -
0.8 V to -0.5V). LightPointe provides a distance vs. voltage reading chart for the AireLink 60
system using either the integrated or the external antenna options (see Figure 5-8). When
using the
Lightpointe BLE Tool , the RSSI reading is given in dBm directly.
9. To align the system turn the Azimuth and Elevation Adjustment Screws at each antenna
left/right for best azimuth alignment and up/down for best elevation alignment and observe the
voltmeter or Android software reading. The goal is to find the maximum RSSI voltage reading
(lowest negative voltage) on both sides of the link. Using a meander-like scan pattern has
proven to be the most efficient way to align the antennas. This is illustrated in Fig. 5-6.
Figure 5-6: Antenna alignment scan