Elation Professional DMX 101 User Manual

Page of 24
DMX 101:  A DMX 512 Handbook
12
Elation Professional ®
While 4000 feet may be specified by the standard, most manufacturers recommend DMX runs of no more than 
1000 feet (300 feet between devices) before using a repeater to regenerate the signal.  Each device should have 
input and output connectors, but these are usually wired together.  No re-transmission or amplification is 
performed.
Devices are connected in a daisy-chain fashion, from the controller to device #1, then device #1 to device #2, and 
so on.  The final device in the daisy-chain must be terminated.  The terminator absorbs signal power which 
would otherwise be reflected back into the cable and degrade the data.  A terminator simply places a 110-120 
Ohm, 0.5 Watt resistor across the two transmission wires.
NOTE:  DMX cannot be split reliably by making Y-cables or T-connectors.  DMX splitter/repeaters (such 
as the Elation Opto Branch 4) typically use optical isolation to protect each segment from electrical 
faults on other branches.  These can be used to increase the number of devices on one network 
beyond the limit of 32.  Each branch of a splitter/repeater can support up to 32 devices.
3