Appendix, DMX Primer, Fixt URE Linking | Chauvet DMX-250C instruction

APPENDIX

DMX Primer

There are 512 channels in a DMX-512 connection. Channels may be assigned in any manner. A fixture capable of receiving DMX 512 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 all respond exactly the same.

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+). CHAUVET carries 3-pin XLR DMX compliant cables, DMX-10 (33’), DMX-4.5 (15’) and DMX-1.5 (5’)

FIXT URE LINKING

Figure 4 - DMX connector configuration

COMMON

	1	DMX +
INPUT	3	DMX +
INPUT	3
	2	DMX -
		DMX -

	1	Resistance 120
		ohm 1/4w between
	3
		pin 2 (DMX -) and

2pin 3 (DMX +) of the last fixture.

3	OUTPUT
2	Termination reduces signal errors and to
	avoid signal transmission problems and
	interference, it is always advisable to connect
	a DMX signal terminator.

Note!	If you use a controller with a 5 pin DMX output connector, you will need to use a 5
	pin to 3 pin adapter. Chauvet Model No: DMX5M.
	The chart below details a proper cable conversion:

3PIN TO 5 PIN CONVERSION CHART

CONDUCTOR

GROUND/SHIELD

DATA ( - )SIGNAL

DATA ( + ) SIGNAL

DO NOT USE

3 Pin Female (output)

Pin 1

Pin 2

Pin 3

5 Pin Male (Input)

Pin 1

Pin 2

Pin 3

Do not use

DMX-250C User Manual

Revision: 5/17/2005 10:49 PM