Afar AR-24010E, Руководство оператора

Страница: 39 / 108

pulsAR radio Operator's Manual
Parameter Description Command
RF channel You may need to change the RF channels if there is interference
on the default channel (12). You can configure the RF transmit
channel independently from the RF receive channel. Refer to
section 3.2.7 for the procedure for choosing new channels. rf-1-setup
rf-2-setup
RF transmit
power The factory default is 18 dBm. You can configure this parameter
in 1 dB increments from 0 to 27 dBm. Take care not to exceed
the maximum power limits as described in sections 3.2.8 or 3.2.9 rf-1-setup
rf-2-setup
Node type In the simple point-to-point and point-to-multipoint topologies
only one radio needs to be configured as the hub. In the Tree
topology (and Linear Network or Loop) you will use node types
of
root , branch , and leaf . Refer to section 2 for details.
node
Network ID The default value is 0. Change this value in all radios to a unique
number to avoid unauthorized radios from joining the network.
node
3.2.7 Spectrum Analysis and channel selection
Radio operation in unlicensed bands has the potential of suffering from interference from other
equipment operating in the same band. The use of directional antennas greatly reduces the potential
for interference. In addition, the p
ulsAR radio includes several features, described below, to identify
and overcome sources of interference.
The radio can be commanded to perform a spectrum analysis of the ISM band and report the results in
either a graphical or tabular form. The command:
> spectrum-analysis antenna=a dwell=xx
instructs the radio to scan the entire band, dwelling on each channel for a programmable amount of
time, and record the highest signal level in that channel. This feature can be used to perform a site
survey and identify the best receive channel.
Note that the RSSI value reported for each channel represents the total energy within the radio RF
bandwidth centered around that channel. The radio RF bandwidth depends on the pulsAR model and
can be 1.7, 4.6, or 17 MHz (see specification in appendix B). When you do a spectrum analysis any
single channel sample that shows a low “noise” level, is a good candidate to select as a receive
channel.
Once you identify a potential receive channel using the spectrum analysis tool, you may then use the
“timing analysis” feature to confirm that the selected channel is indeed clear. The command:
>time-analysis channel=xx antenna=a dwell=xx
3-9