Moore Industries WLM, Руководство по установке

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22 The Interface Solution Experts
WLM
WLM Location Selection
Placement of your WLM is likely to have a significant impact on its performance. In general, the rule of thumb with
the WLM is that the higher the placement of the antenna the better the communication. In practice you should also
place the radio modem itself away from computers, telephones, answering machines, and other similar equipment.
To improve the data link, Moore Industries-International, Inc. offers directional and omni directional antennas with
cable lengths ranging from 10 to 200 feet. Consult the factory if cable lengths longer than 200 feet are required.
When using an external antenna, placement of that antenna is critical to a solid data link. Other antennas in close
proximity are a potential source of interference. It is also possible that slight adjustments in antenna placement (as
little as 2 feet) will solve noise problems. In extreme cases, such as when the radio modem is located close to pager
or cellular telephone transmission towers, Moore Industries-International, Inc. offers a band pass filter to reduce the
out of band noise.
Using an External Antenna
In certain circumstances it may be desirable to extend the range of the WLM radio modem by using an external
antenna in place of the standard whip antenna. The radio modem is equipped with a standard SMA external jack.
This allows the use of a directional Yagi or omni directional antennae kits provided by Moore Industries-International,
Inc.
The use of an external antenna may radically improve the results obtained with WLM radio modems. It is imperative
to obtain line-of-sight with the antennas, and changes in placement height of as few as a couple of feet may make
the difference between no link and one that is solid and reliable.
Moore Industries-International, Inc. offers a variety of omni directional and directional external antennae, with both
bracket and magnetic mounts. These antennas allow versatility in the WLM’s deployment, extending its range and
allowing it to get around obstructions.
If external directional antennas are used, FCC regulations concerning effective radiated power limitations must be
followed.
Caution : Any antenna placed outdoors must be properly grounded. It is required by FCC regulations that
qualified personnel experienced in antenna installation and familiar with local codes and regulations
complete the antenna installation. It is also required by FCC regulations that only approved antennas be
used. Use extreme caution when installing antennae and follow all instructions included with the antennas.
The use of external antennae subjects the radio modem to greater exposure to direct lightning strikes. It is strongly
recommended that a lightning arrestor be used on all outdoor antenna installations.