Chauvet 350 Manuale Utente

Page 24 of 26

Intimidator™ Spot LED 350 User Manual (Rev. 02)

(DMX Connectivity cont.)

Number of Fixtures

When using a DMX controller, the combined number of channels required by

all the fixtures on the DMX daisy chain determines the number of fixtures the

DMX controller has to support. Conversely, the number of onboard sliders,

page buttons, and fixture buttons limits the number of discrete DMX channels

a DMX controller can support.

To comply with the EIA-485 standard, which is the base for the USITT

DMX512-A protocol, do not connect more than 32 fixtures without using

an optically-isolated DMX splitter. Doing otherwise may result in

deterioration of the digital DMX signal.

DMX Data Cabling

You must use DMX compliant data cables to link two or more DMX compatible

fixtures. You may purchase CHAUVET® certified DMX cables directly from a

dealer/distributor or construct your own cable.

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).

Making Your Own

DMX Cable

If you choose to create your own DMX cable, make sure to use data-grade

cables that can carry a high frequency signal and are less prone to

electromagnetic interference. Use a Belden® 9841 or equivalent cable, which

meets the specifications for EIA RS-485 applications. For certain applications,

Cat5, Cat5e, or Cat6 may be appropriate.

Do not use standard microphone cables for DMX applications because

they cannot transmit DMX data reliably over long distances.

DMX Cable Characteristics

The DMX data cable must have the following characteristics:

Type:

shielded, 2-conductor twisted pair

Maximum capacitance between conductors:

30 pF/ft

Maximum capacitance between conductor and shield:

55 pF/ft

Maximum resistance:

20 ohms/1000 ft

Nominal impedance:

100~140 ohms

DMX Cable Connectors

Each DMX cable must have a male (3-pin or 5-pin XLR connector) on one end

and a female (3-pin or 5-pin XLR connector) on the other end.

To avoid signal transmission

problems and interference,

connect a DMX signal terminator

to the last fixture in the

DMX daisy chain, as shown.

To DMX Input

(Female)

DMX Connector Configuration

Common

DMX +

DMX -

To DMX Output

(Male)

120 ohm, ¼ W
resistor between
pin 2 (DMX -) and
pin 3 (DMX +) on
the output of the
last fixture.