Expression 3 - ETC

Moving light concepts and terms
Fixtures
Conventional lights, sometimes called fixtures, are single attribute
devices whose intensity can be controlled by a console connected to a
dimmer. In this User Manual, however, the term fixture is often used to
refer to multi-attribute devices such as moving lights to distinguish them
from conventional lights. The programming methods in this manual apply
to any multi-attribute device controlled by DMX512 as to moving lights.
Fixture attributes
Every fixture has a set of attributes that you use to control it. For instance,
a basic moving light might have only three attributes: intensity, pan and
tilt. You control the fixture’s brightness by adjusting the level of a DMX512
channel that controls a dimmer assigned to the fixture. Similarly, you
control the fixture’s horizontal and vertical movements by adjusting the
levels of DMX512 channels assigned to the fixture’s pan and tilt attributes.
This simple fixture would require three channels to fully control it. Other,
more complicated fixtures could have additional attributes such as color,
focus or gobo, and each additional attribute would require an additional
DMX512 channel to control it.
In contrast, a standard ellipsoidal spotlight needs only one DMX512
channel to fully control it, namely the one that controls the dimmer
assigned to the spotlight. Only the spotlight’s intensity can be controlled
by changing the channel level. It has no other attributes.
Categories
Most attributes can be naturally categorized as affecting the beam, the
image, the color or the position. All attributes are initially assigned to one
of these four categories or to a fifth one called None. Beam attributes
include Intensity, Zoom, Focus, Iris, and Frost. Image attributes include
Gobo and F/X. Color attributes include Color, Cyan, Magenta, and Yellow.
Position attributes include Pan and Tilt. You can customize the
assignment of attributes to categories, including assigning an attribute to
multiple categories and assigning as many attributes as you want to a
single category.
Personalities
Every fixture has an electronic personality that describes how it can be
controlled. The personality specifies the attributes for the fixture and the
order in which these attributes are presented to DMX512 channels.
Assigning a personality to a fixture makes channel patching quick and
easy. All you need to do is define which console channels and DMX512
addresses are first—the personality directs the rest of the assignment.
Many personalities are included with the console software. Other
personalities for leading moving light fixtures on the market are being
developed by ETC. As additional personalities become available, these are
made available to dealers and placed on the ETC website for downloading.
Also available from dealers and at the website is a program called the
Expression Personality Editor which enables you to create and edit
fixture personalities on an IBM-compatible computer. For further
information about these options, call ETC Technical Services at
800-775-4382 or visit the ETC website at www.etcconnect.com.
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