Acclaim Lighting DDC-1-AC, User Manual

Page: 8 / 14

6
www.acclaimlighting.com
DALI
PSU
DALI DMX
1 2 3 4 5 6 7 8 9 10 11 12
ON
DMX ADDRESS SETTING
DALI
Controller
DMX
Fixture
DMX
Fixture
DMX
Fixture
DMX
Fixture
T
TIPS FOR ACHIEVING SUCCESSFUL
DMX
CONTROL
•
Do not exceed a total cable length of 3,900 ft (1200m) without buffering.
•
Do not exceed a total of 32 devices/fixtures on a single line without buffering.
•
Use only connection cables with a characteristic impedance of 120Ω, preferably where
the DMX + and DMX – data lines are twisted around each other and the ground link exists
as a coaxial screen surrounding the inner cores, such as Belden® 9842 or equivalent.
•
Connect a 120Ω terminating resistor between the DMX + and DMX – output connections
of the final fixture.
•
Do not introduce a passive Y-split into the control cabling. If it is necessary to split the
control link in order feed fixtures located in different directions, use a powered DMX
splitter/buffer.
•
Ensure that the DMX + and DMX – connections do not become crossed at any point.
DMX LAYOUT
DMX provides much higher data speeds than DALI and as a result imposes much stricter
cabling requirements. A linear bus must be formed, using very specific cable types (see
below), which must be terminated at each end (the DDC-1-AC unit is internally terminated).
Polarity of all connections is critical and up to 32 fixtures can be connected along the
bus. Any branches from the main bus must be kept to an absolute minimum and active
buffering is required to connect more than 32 fixtures or to create a Y-split.
A typical DMX bus layout