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Fixture Linking
You will need a serial data link to run light shows of one or more fixtures using a DMX controller or to
run synchronized shows on two or more fixtures set to a master/slave operating mode. The combined
number of channels required by all the fixtures on a serial data link determines the number of fixtures
the data link can support.
The fixtures must be linked using DMX cable in a daisy chain (serial) fashion. To comply with
the EIA-485 standard, no more than 32 fixtures should be connected on one daisy chain
without using a DMX optically-isolated splitter. Doing otherwise may result in deterioration of
the digital DMX signal.
USITT recommends limiting the total length of the DMX cable (from the first fixture/controller
to the last fixture) to 300 ~ 455 m (985 ~ 1,500 ft).
Data Cabling
To link fixtures together you must obtain data cables. You can purchase CHAUVET certified DMX
cables directly from a dealer/distributor or construct your own cable. If you choose to create your own
cable, please use data-grade cables that can carry a high quality signal and are less prone to
electromagnetic interference.
DMX Data Cable
Use a Belden© 9841 or equivalent cable which meets the specifications for EIA RS-485 applications.
Standard microphone cables cannot transmit DMX data reliably over long distances. The cable must
have the following characteristics:
Type:
Maximum capacitance between conductors:
Maximum capacitance between conductor and shield:
Maximum resistance:
Nominal impedance:
Cable Connectors
The cable must have a male XLR connector on one end and a female XLR connector on the other
end.
DMX connector configuration
1
INPUT
3
2
Do not allow contact between the common and the fixture's chassis ground. Grounding the
common can cause a ground loop, and your fixture may perform erratically. Test cables with
an ohmmeter to verify correct polarity, and to make sure the pins are not grounded or shorted
to the shield or each other.
COLORdash™ Block User Manual
COMMON
1
DMX +
3
2
-
DMX
10
shielded, 2-conductor twisted pair
20 ohms/1000 ft
100 – 140 ohms
120 ohm, ¼ W
1
resistor between
3
pin 2 (DMX -) and
2
pin 3 (DMX +) on
the output of the
last fixture.
OUTPUT
To avoid signal transmission
problems and interference, it is
always advisable to connect a DMX
signal terminator.
30 pF/ft
55 pF/ft
6/19/2009 4:54 PM
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