American DJ
®
- www.americandj.com - Comscan LED Instruction Manual Page 6
American DJ
®
- www.americandj.com - Comscan LED Instruction Manual Page 5
Power Supply:
The American DJ
®
Comscan LED contains an elec-
tronic ballast, which will auto sense the voltage when it is plugged into
the power source. With the electronic ballast you do not need to worry
about wall voltage, this unit can be plugged in anywhere. Also be sure
to only use the included I.E.C. power cable supplied with the unit.
DMX-512:
DMX is short for Digital Multiplex. This is a universal pro-
tocol used by most lighting and controller manufactures as a form of
communication between intelligent fixtures and controllers.
A DMX
controller sends DMX data instructions from the controller to the fix-
ture. DMX data is sent as serial data that travels from fixture to fixture
via the DATA “IN” and DATA “OUT” XLR terminals located on all DMX
fixtures (most controllers only have a DATA “OUT” terminal).
DMX Linking:
DMX is a language allowing all makes and models
of different manufactures to be linked together and operate from a
single controller, as long as all fixtures and the controller are DMX
compliant.
To ensure proper DMX data transmission, when using
several DMX fixtures try to use the shortest cable path possible. The
order in which fixtures are connected in a DMX line does not influence
the DMX addressing. For example; a fixture assigned a DMX address
of 1 may be placed anywhere in a DMX line, at the beginning, at the
end, or anywhere in the middle. Therefore, the first fixture controlled
by the controller could be the last fixture in the chain. When a fixture
is assigned a DMX address of 1, the DMX controller knows to send
DATA assigned to address 1 to that unit, no matter where it is located
in the DMX chain.
Data Cable (DMX Cable) Requirements (For DMX and Master/Slave
Operation):
The Comscan LED can be controlled via DMX-512 pro-
tocol. The Comscan LED is a five channel DMX
unit. The DMX address is set electronically using
the controls on the rear panel of the unit. Your unit
and your DMX controller require a approved DMX-
512 110 Ohm Data cable for data input and data
output (Figure 1). We recommend Accu-Cable DMX
cables. If you are making your own cables, be sure
to use standard 110-120 Ohm shielded cable (This
cable may be purchased at almost all professional
sound and lighting stores). Your cables should be made with a male
Comscan LED
Set Up
Figure 1
and female XLR connector on either end of the cable. Also remember
that DMX cable must be daisy chained and cannot be split.
Comscan LED
Set Up
Notice:
Be sure to follow figures two and three when making your own
cables. Do not use the ground lug on the XLR connector. Do not con-
nect the cable’s shield conductor to the ground lug or allow the shield
conductor to come in contact with the XLR’s outer casing. Grounding
the shield could cause a short circuit and erratic behavior.
Figure 3
1 Ground
1 Ground
XLR Male Socket
XLR Pin Configuration
3 Hot
2 Cold
2 Cold
3 Hot
XLR Female Socket
Pin 3 = Data True (positive)
Pin 2 = Data Compliment (negative)
Pin 1 = Ground
Special Note: Line Termination.
When longer runs of cable are
used, you may need to use a terminator on the last unit to avoid erratic
behavior. A terminator is a 110-120 ohm 1/4 watt resistor which is con-
nected between pins 2 and 3 of a male XLR connector (DATA + and
DATA -). This unit is inserted in the female XLR connector of the last
unit in your daisy chain to terminate the line. Using a cable terminator
(ADJ part number Z-DMX/T) will decrease the possibilities of erratic
behavior.
Figure 2
DMX512 IN
3-PIN XLR
1
2
3
1
2
3
DMX +
DMX -
COMMON
DMX512 OUT
3-PIN XLR
Figure 4
1
2
3
Termination reduces signal errors and
avoids signal transmission problems
and interference. It is always advisable
to connect a DMX terminal, (Resistance
120 Ohm 1/4 W) between PIN 2 (DMX-)
and PIN 3 (DMX +) of the last fixture.
