Honeywell XYR 400E User Manual page 13

Plant and factory installations
Most installations in industrial plants and factories use a single omni-directional antennas.
Installations can suffer from "multi-path fading" effects where multiple reflected radio signals
adversely affect the signal strength. This can be checked by moving the antenna a short distance
(10 cm or 4 inches) - if the signal increases significantly then there are multi-path effects.
In a "static" installation, where the radio path is not changing, moving an antenna to the
position of maximum signal solves this problem. However where the radio path changes because
the XYR 400E is mounted on moving equipment, or if there is moving equipment in the area,
then the solution is to use two antennas. Because the two connectors are separated, the RF
signal at each connector will be different in the presence of multi-path fading. The XYR 400E
unit will automatically select the higher RF signal.
Note that directional antennas are not normally used in plant and factory installations.
Line-of-sight installations
In longer line-of-sight installations, the range may be increased by using a high gain antenna on
the TX/RX connector. However the gain should not cause the effective radiated power (ERP) to
exceed the permitted value. A second higher gain antenna can be connected to the RX connector
without affecting ERP - this will increase the operating range provided the background noise in
the area is low.
Antennas
Antennas can be either connected directly to the module connectors or connected via 50 ohm
coaxial cable (eg RG58 Cellfoil or RG213) terminated with a male SMA coaxial connector. The
higher the antenna is mounted, the greater the transmission range will be, however as the length
of coaxial cable increases so do cable losses.
The net gain of an antenna/cable configuration is the gain of the antenna (in dBi) less the loss in
the coaxial cable (in dB). The maximum net gain of the antenna/cable configuration connected
to the TX/RX connector is 0dB in Europe (100mW ERP). In USA, Canada and Australia (4W
ERP), the maximum gain is 12dB for the XYR 400E-300 or 16dB for the XYR 400E-100.
There is no gain restriction for antennas connected to the RX connector.
13 XYR400E Ethernet Modem Version 1
5/1/08