22
1981
2011
-0
7
82
WHA-GW-*
Operation
Figure 6.14Eliminating a bottleneck
Expand the Network
In an industrial environment, there are several potential obstacles for radio waves, for
example buildings, walls, pipes, or even moving obstacles like trucks. Those obstacles can
reflect, bend, diffuse or block radio waves. The effects of reflection, bending and diffusion
create new waves which interact with the original ones and with each other. They can
amplify or nullify each other.
Due to the interference of reflections, moving the antenna a few centimetres can help. If
there are obstacles blocking transmission between wireless devices, add additional
devices to provide alternative communication paths. The more devices exist in a
Wireless
HART network, the more reliable it gets.
Optimize Coexistence with other
Wireless
Networks
Wireless
HART networks use the frequency spectrum between 2400 ... 2483.5 MHz
according to IEEE 802.15.4. Various other wireless technologies also use this frequency
spectrum, for example WLAN (IEEE 802.11) and Bluetooth (IEEE 802.15.1). Measures
must be taken to ensure that the various wireless technologies do not affect each other.
1
Bottleneck
2
Wireless
HART Gateway
3
Possible position of an additional
Wireless
HART device eliminating the bottleneck
