Leprecon LD-340 DMX Series - Manual (Page 7)

DMX 512 Standards
The following information is a summary of the USITT 1990 standard for dimmers and controllers.
A complete copy may be obtained from:
USITT
10 W. 19th ST.
Suite 5A
New York, NY 10011-4206
The DMX 512 standard is designed as a simple, reliable system for connecting digital dimmers
and controllers. The protocol allows up to 512 dimmers to be connected to a single control
console. With 512 dimmers in a system, DMX 512 allows each dimmer level to be updated 44
times each second.
Connectors
The DMX standard specifies the use of 5 pin XLR connectors. DMX 512 currently uses 3 pins of
the 5 pin connector. Pins 4 and 5 are reserved for future use; some manufacturers are using
these pins for communications back from the dimmer to the control console, or as a redundant
data line. At this time, DMX cables are being used that only contain 3 wires. If you wish to include
the capability to use the extra pins, it is suggested that you buy or make cables with all 5 pins
connected.
The connectors to be used for DMX 512 are as follows:
Console end (transmitter) Female 5 pin XLR
Dimmer end (receiver) Male 5 pin XLR
Some manufacturers of XLR connectors are Switchcraft, ITT Cannon, and Neutrik.
Cable type
Shielded twisted pair approved for EIA-422/EIA-485 use. Either one pair with shield or two pair
with shield may be used. Examples of such cable are:
Single pair: Belden 9841, Alpha 5271
Two pairs: Belden 9842, Alpha 5272
The Pin Designations for DMX 512 are as follows:
Pin 1 Signal common (cable shield)
Pin 2 Data 1-
Pin 3 Data 1+
Pin 4 Spare, optional Data 2-
Pin 5 Spare, optional Data 2+
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