4.4. DMX512 Connections
The DMX512 is widely used in intelligent lighting control, with a maximum of 512 channels.
1.
At last unit, the DMX cable has to be terminated with a terminator. Solder a 120-ohm 1/4W
resistor between pin 2(DMX-) and pin 3(DMX+) into a 3-pin XLR-plug and plug it in the
DMX-output of the last unit.
2.
Connect the unit together in a “daisy chain” by XLR plug cable from the output of the unit to
the input of the next unit. The cable cannot be branched or split to a “Y” cable. DMX 512 is a
very high-speed signal. Inadequate or damaged cables, soldered joints or corroded connectors
can easily distort the signal and shut down the system.
3.
The DMX output and input connectors are pass-through to maintain the DMX circuit, when
one of the units’ power is disconnected.
4.
Each lighting unit needs to have a DMX address to receive the data by the controller. The
address number is between 0-511 (usually 0 & 1 are equal to 1).
5.
The end of the DMX 512 system should be terminated to reduce signal errors.
6.
3 pin XLR connectors are more popular than 5 pins XLR.
3 pin XLR: Pin 1: GND, Pin 2: Negative signal (-), Pin 3: Positive signal (+)
5 pin XLR: Pin 1: GND, Pin 2: Negative signal (-), Pin 3: Positive signal (+), Pin4, Pin5 not used.
13B