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8. APPENDIx
dMX priMer
There are 512 channels in a DMX connection. Channels may be assigned in any manner. A fixture capable of receiving
DMX will require one or a number of sequential channels. The user must assign a starting address on the fixture that
indicates the first channel reserved in the controller. There are many different types of DMX controllable fixtures and
they all may vary in the total number of channels required. Choosing a start address should be planned in advance.
Channels should never overlap. If they do, this will result in erratic operation of the fixtures whose starting address is set
incorrectly. You can however, control multiple fixtures of the same type using the same starting address as long as the
intended result is that of unison movement or operation. In other words, the fixtures will be slaved together and will all
respond exactly the same. Consult the Owner’s Manual to your DMX controller for more information.
DMX fixtures are designed to receive data through a serial Daisy Chain. A Daisy Chain connection is where the DATA
OUT of one fixture connects to the DATA IN of the next fixture. The order in which the fixtures are connected is not
important and has no effect on how a controller communicates to each fixture. Use an order that provides for the easiest
and most direct cabling. Connect fixtures using shielded two-conductor twisted pair cable with three pin XLR male to
female connectors. The shield connection is pin 1, while pin 2 is Data Negative (S-), and pin 3 is Data Positive (S+).
general trouBleShooting
SyMptoM
poSSiBle cauSe(S)
poSSiBle action(S)
Breaker/Fuse keeps blowing
• Excessive circuit load
• Short circuit along the power wires
• Check total load placed on the electrical circuit.
• Check for a short in the electrical wiring (internal and/
or external).
Device does not power up
• No power
• Loose power cord
• Check for power on Mains.
• Check power cord
Fixture is not responding to DMX
• Wrong DMX addressing
• Damaged DMX cables
• Wrong polarity settings on the controller
• Loose DMX cables
• Faulty DMX interface
• Faulty Main PCB
• Check Control Display and unit addressing
• Check DMX cables
• Check polarity switch settings on the controller
• Check cable connections
• Replace DMX input
• Replace Main PCB
Loss of signal
• Non DMX cables
• Bouncing signals
• Long cable / Low level signal
• Too many fixtures
• Interference from AC wires
• Use only DMX compatible cables
• Install terminator as suggested
• Install amplifier right after fixture with strong signal
• Install an optically coupled DMX splitter after unit #32
• Keep DMX cables separated from power cables or
black light
