Obsession™ LED 2.0 User Manual (Rev. 03)
Page 17 of 20
DMX Configuration
The DMX fixture configuration consists in determining how many channels
each fixture will need as well as assigning the corresponding DMX channels to
each fixture in order to size correctly the DMX controller.
Personalities
A DMX personality describes what channel or channels control which fixture
parameters. A DMX fixture may have many personalities to choose from. Each
personality requires a different number of channels, based on the number of
features the fixture enables. The number of DMX channels used by a fixture
may vary from only one (usually the general dimmer control) to 15 or more.
When a job does not require using all the fixture’s capabilities, the user can
select a more basic personality (less channels), allowing the DMX controller to
accommodate more DMX fixtures.
Starting Address
For the DMX controller to control each DMX fixture, the user must first
configure each fixture’s personality to determine the number of channels
required to control the fixture. Each channel will have a DMX address
assigned to it.
However, since assigning a particular DMX address to each channel is
impractical, the user will only need to configure the DMX address on each
fixture that corresponds to the fixture’s first channel of control. This is the
fixture’s starting address. The fixture will automatically assign the other
channels to the subsequent DMX addresses.
Once this assignment is complete, and based on the number of channels
used, the fixture will respond to the DMX signals sent to the range of DMX
channels that begins with the starting address.
For example, a fixture that uses six DMX channels with a starting address of
100, will accept DMX data sent by the DMX controller to channels 100, 101,
102, 103, 104, and 105.
Assigning Addresses
The user must carefully assign the starting addresses for each individual
fixture to avoid DMX channel overlapping. If the DMX channels do overlap, the
impacted fixtures could operate erratically.
However, the user may decide to configure two or more similar fixtures with
the same personality and starting address. In this case, all the fixtures with the
same starting address will operate in unison.
DMX Connectivity
Connecting the DMX fixtures to a DMX controller in small to medium
installations is usually a rather simple operation that requires a minimum of
tools and some planning (not including the actual fixture rigging and
configuration).
However, in large installations it may be necessary to plan carefully the
position and cabling of each fixture to avoid unexpected problems.
Fixture Location
The order in which the fixtures connect to the DMX controller is not important
and has no effect on how a controller communicates to each fixture. However,
the user should always define a physical location for the fixtures that provides
for the easiest and most direct cabling to the controller and other fixtures.
