Microhard Systems MRX-900, Operating Manual

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MRX-900 Operating Manual: Configuration Options
11
Test the communications
link using a low power level
and work upward. Avoid
using a higher power than
necessary since performance
may actually degrade.
Warning: When transmitting
at the full power of 1W, FCC
regulations prohibit using an
antenna with a gain greater
than 6 dBi (6 dB above
isotropic gain).
3.7 Encryption Key
The Encryption Key provides a measure of security and privacy of
communications by rendering the transmitted data useless without the correct
key on the receiver. By selecting option 7 from the configuration menu, you
are prompted to enter a key (valid values range from 0 to 65535), followed
by Return or Enter:
Encryption Key = 6109
ESC to exit
Set Encryption Key : _
Keep in mind that all units within the network must use the same key for
communications to succeed.
3.8 Output Power Level
The Output Power Level determines at what power the MRX-900 transmits.
The super-sensitive MRX-900 can operate with very low power levels, so it
is recommended that the lowest power necessary is used; using excessive
power contributes to unnecessary “RF polution”. To set the power level,
select option 8 from the configuration menu and select one of the following:
Power Output Level
1) 1 mW
2) 10 mW
3) 100 mW
* 4) 1000 mW
5) Adaptive
ESC to exit
Select Power Output Level : _
Ideally, you should test the communications performance between units
starting from a low power level and working upward until the RSSI is
sufficiently high and a reliable link is established. Although the conditions
will vary widely between applications, typical uses for each setting are
described below:
Power Use
1 mW For in-building use, typically provides a link up to 300 feet on the
same floor or up/down a level. Outdoors, distances of 10 km can be
achieved if high-gain (directional) antennas are placed high above
ground level and are in direct line-of-sight.
10 mW 200-500 ft indoors, 8-15 km outdoors.
100 mW 400-800 ft indoors, 15-25 km outdoors.
1000 mW
(1 W)
Typically provides communications up to a distance of 1000 feet or
more in-building on the same floor or up/down a few levels,
depending on building construction (wood, concrete, steel, etc.). In
ideal outdoor conditions, up to 30 km or more can be achieved.
Note that only an antenna with a gain of no more 6 dBi may be used.
Any higher is a violation of FCC rules.
Adaptive Used in noisy environments where interference may vary. Power
may change over time. Note that only an antenna with a gain of no
more 6 dBi may be used. Any higher is a violation of FCC rules.