The SHoW DMX Wireless Data System
User’s Manual
Rev 1.4 11-17-08
31 of 48 Pages
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Outdoors, locate the Transmitter and Receiver(s) up high on a secure mounting
position such as a truss, pole or other firm platform such as the edge of a
building roof.
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Indoors, locate the Transmitter and Receiver(s) so they are above the floor and
equidistant from other planar surfaces such as ceilings, walls etc.
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Locate the Transmitter and Receiver(s) so that there are no radio barriers
between them. Radio barriers can be any solid object, but metal and water are
high on the list.
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Position the antennas so that they are parallel to each other. Monitor the
received signal strength on the Receiver(s) while adjusting antenna positions to
arrive at the best signal strength. Usually the best position will be vertical and
parallel, but not always.
Environmental considerations can affect range. The presence of water in the broadcast
area can reduce range, whether as evaporation off a lake or pond, rain or snow, a crowd
of people (bodies are mostly water), or trees and large plants.
Once the Transmitter and Receiver(s) are installed and running, check the received
signal strength on the Receiver(s), and adjust the Transmitter broadcast power until the
signal strength is in the -70~50 dBi range.
For best results, test your system under the conditions it will be used. A large empty
room will have different radio characteristics than the same room filled with people.
Configuring a Transmitter/Receiver pair for optimal reception
The optimal setup for a basic single Transmitter / single Receiver system will include a
number of steps.
1.
Select a location for the Transmitter
. Ideally the Transmitter should be located
reasonably high in the air within the venue where it is being used, with a clear
line of sight to the Receiver position. The goal is to get it away from the ground
or floor and above RF absorbing obstacles such as people, trees and plants,
metal or glass structures, fountains, or thick barriers of other materials. In a
conventional theater, good locations usually include a balcony rail position or on
one of the fixture positions over the stage. For outdoor/architectural installations,
the transmitter could be mounted on a pole or on the roof of a building. Even
mounting in a tree could be good, but be aware that the branches, trunk, and
leaves of a live tree can be a significant radio barrier because they contain a lot
of water.
2.
Select a location for the Receiver.
Normally the Receiver’s location will be
dictated by the application, as you will need it to be near where the DMX512
devices are located that need wireless control. Common theatrical locations
include on (or in) a set piece, on a pipe or truss, or even in a prop or costume.
outdoor/architectural installations might call for Receiver to be on another
building, an amusement attraction, or near a temporarily installed lighting unit
such as a moving light.
Sometimes the receiver must be concealed; That’s OK! SHoW DMX can “burn
through” many kinds of barriers and go around corners. If you need to conceal
your receiver, try to avoid putting it behind or inside things that are RF barriers,
