Phoenix Contact UM EN FL WLAN EPA, Руководство пользователя

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Additional information
8099_en_02 PHOENIX CONTACT
4-3
Calculation for 2.4 GHz: free space attenuation [dB] = 100 + 20log distance [km]
Calculation for 5 GHz*: free space attenuation [dB] = 106 + 20log distance [km]
* The 5 GHz band for WLAN covers a frequency range of more than 600 MHz. This results
in different attenuation values, depending on the frequency used. The formula gives a
proper average value. Exact values can be calculated with the following formula: free space
attenuation [dB] = 32.4 + 20log frequency [MHz] + 20log distance [km]
4.1.4 Propagation of the radio wave indoors
4.1.4.1 In an industrial hall
If the wireless unit is installed in an industrial hall, the conditions listed above basically apply.
The Fresnel zone will not be free there. But reflections on metal objects may promote the
propagation of radio waves.
The range of the wireless modules depends on their mounting location and/or the position
of their antennas.
In general the antenna should be free from other objects, so it can radiate well into the area.
It should, for example, not be touched by cables or be surrounded by a metal control
cabinet.
The reference value for the range within an industrial hall is up to 50 meters. The actual
range may be significantly greater or less than this. The variation depends on the
environment and the transmission power set. Large metal obstacles, such as walls or
machines, may limit the range in that direction. This is particularly true if they are
permanently located (static) between the wireless units.
The range can be limited by reducing the transmission power. Thus, only certain areas can
be covered, if desired.
350 90.9 dB 96.9 dB
400 92.0 dB 98.0 dB
450 93.1 dB 99.1 dB
500 94.0 dB 100.0 dB
550 94.8 dB 100.8 dB
600 95.6 dB 101.6 dB
650 96.3 dB 102.3 dB
700 96.9 dB 102.9 dB
750 97.5 dB 103.5 dB
800 98.1 dB 104.1 dB
850 98.6 dB 104.6 dB
900 99.1 dB 105.1 dB
950 99.6 dB 105.6 dB
1000 100.0 dB 106.0 dB
Table 4-2 Free space attenuation at 2.4 GHz and 5 GHz
Distance in m Attenuation at 2.4 GHz Attenuation at 5 GHz