User's Manual

Spread Spectrum Wireless Data Transceiver User Manual
LUM0002AF Rev D Version 6.3 42
hop channel are shown in the frequency table. Pressing the Enter key when the Radio Statistics menu is
displayed, accesses the frequency table.
Ideally, noise levels should be below 70 J units and the difference between the average signal level and
average noise level should be 26 or more. Noise levels significantly higher than this are an indication of a
high level of interference that may degrade the performance of the link. High noise levels can often be
mitigated with band pass filters, antenna placement or antenna polarization.
A
VERAGE SIGNAL LEVEL
The average signal level indicates the level of received signal at this transceiver and at each of the
Repeaters in the link. For each of these, the signal source is the transceiver that transmits to it. The
number is an average of the received signal levels measured at each frequency in the transceiver's
frequency hop table. The individual measurement values at each frequency hop channel are shown in the
frequency table. Pressing the Enter key when the Radio Statistics menu is displayed accesses the
frequency table. For a reliable link, the margin should be at least 26 J units. Low Average Signal Levels
can often be corrected with higher gain antennas, better antenna placement and/or additional Repeaters.
Note: Please consult the install manual for antenna and FCC requirements.
O
VERALL RCV RATE (%)
The Overall Receive Rate measures the percentage of data packets that were successfully transmitted
from the Master to the Slave on the first attempt. A number of 75 or higher indicates a robust link that will
provide very good performance even at high data transmission rates. A number of 15 or lower indicates a
weak or marginal link that will provide lower data throughput. An Overall Receive Rate of 100% will
provide approximately 100 KBaud of bandwidth with an RF Data Rate setting of 3 and approximately 150
KBaud of bandwidth with an RF Data Rate of 2. These numbers are reduced approximately 50% if one or
more Repeaters are in the network.
R
ADIO TEMPERATURE
The Radio Temperature value is the current operating temperature of the transceiver in degrees Celsius.
For proper operation, a FreeWave transceiver must be in the temperature range of -40° to +75° C. Some
of the transceivers are only tested to 0° C. See transceiver specification papers for details.
MultiPoint Parameters
When installing MultiPoint networks it is important to do some up front planning. Unlike Point-to-Point
networks, a Point-to-MultiPoint network requires several parameters are set consistently on all
transceivers in the network. This includes RF data rate, Min and Max Packet Size, and FreqKey.
Note: If several independent MultiPoint networks are to be located in close proximity the planning
becomes more critical. In such cases, it becomes very important to include as much frequency
and time diversity as possible through use of different FreqKey, Min and Max Packet Size, and
Hop Table settings. In some instances the use of the MultiMaster Synch option may be required.
Edit MultiPoint Parameters
Selecting (5) Edit MultiPoint Parameters from the main menu displays the following window: