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DMX Primer
Product Linking (Daisy Chain)
Data Cabling
DMX Data Cable
Page 10 of 15
There are 512 channels in a DMX connection. A product capable of receiving DMX will
require one or a number of sequential channels. The user must assign a starting
address on the product that indicates the first channel reserved in the controller. There
are many different types of DMX controllable products 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 products whose starting address is set incorrectly. You can however, control
multiple products 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 products
will all respond exactly the same.
DMX products are designed to receive data through a daisy chain. A daisy chain
connection is where the DATA OUT of one product connects to the DATA IN of the
next product. The order in which the products are connected is not important and has
no effect on how a controller communicates to each product. Use an order that
provides for the easiest and most direct cabling. Connect products using shielded two
conductor twisted pair DMX data 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+).
You will need a daisy chain to run light shows of one or more products using a DMX
controller or to run synchronized shows on two or more products set to a master/slave
operating mode. The combined number of channels required by all the products on a
daisy chain determines the number of products the data link can support.
To comply with the EIA-485 standard, do not connect more than 32 products on
one daisy chain. Connecting more than 32 products on one daisy chain without
the use of a DMX optically-isolated splitter may result in deterioration of the
digital DMX signal.
Maximum recommended cable distance: 500 m (1640 ft)
Maximum recommended number of products on a daisy chain: 32
To link products 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.
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:
shielded, 2-conductor twisted pair
20 ohms/1000 ft
100 ~ 140 ohms
Gobo Zoom LED 2.0 (Rev. 02)
30 pF/ft
55 pF/ft
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