Black Box MD3310-R2, Руководство пользователя

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INDUSTRIAL MODEM RF115
10. The Modem Location
Placement of your modem is likely to have a significant impact on its performance.
In general, the rule of thumb with the modem is that the higher up the antenna,
the better the communication link. You should also place the modem away from
computers, telephones, answering machines, and other similar equipment. A 6-
foot RS-232 cable will usually provide ample room for placement away from other
equipment. To improve the data link, the modem is offered with a directional or
omnidirectional external antenna with cable lengths ranging from 10 to 100 feet.
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;
use the Radio Statistics to help identify potential problems. 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 modem is located close to pager or
cellular-telephone transmission towers, the modem offers a band-pass filter to
reduce the out-of-band noise.
The standard enclosure for the modem does not provide protection against water
or environmental hazards, and will fade when placed in direct sunlight. For
outdoor applications, use a weather-resistant enclosure.