Chauvet XPress-100, Руководство пользователя

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59 Chauvet® ShowXpress™ V6.22
13. A
PPENDIX
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 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+).
Data Cabling
To link fixtures 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.
DMX Data Cable
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: 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