14
805.281.001
Date: March 22
rd
, 2017
Data link
A DMX 512 data link is required in order to control the rotator via DMX. The Rotator 281 has 5-
pin XLR connectors for DMX data input and output. The pin-out on all connectors is pin 1 =
shield, pin 2 = (data -), and pin 3 = (data +). Pins 4 and 5 in the 5-pin XLR connectors are not used
in the Rotator 281, and there is no connection between the 5-pin XLR in and out connectors.
The Rotator 281 is subject to the common limit of 32 devices per daisy-chained link. Note that if
independent control of a rotator is required, it must have its own DMX channels. To add more
rotators or groups of rotators when the above limit is reached, add a DMX-splitter and another
daisy-chained link.
Tips for reliable data transmission
Use shielded twisted-pair cable designed for RS-485 devices: standard microphone cable
cannot transmit control data reliably over long runs. 24 AWG cable is suitable for runs up to
100 meters (328 ft.).
Never use a rotator’s outputs to split a DMX link. To split the link into branches, use an opto-
isolated RS-485 splitter/amplifier.
Terminate the link by installing a termination plug in the output socket of the last rotator. The
termination plug, which is a male XLR plug with a 120 Ohm, 0.25 Watt resistor soldered
between pins 2 and 3, “soaks up” the control signal so it does not reflect and cause
interference. If a splitter is used, terminate each branch of the link.
Connecting the data link
To connect the Rotator 281 to data:
1.
Connect the DMX data output from the DMX controller to the Rotator 281’s male 5-pin
XLR DMX input connector (DMX 512 IN).
2.
Connect the DMX output of the rotator to the DMX input of the next rotator and
continue connecting rotators output to input (DMX 512 OUT).
3.
Terminate the last rotator on the link with a 120 Ohm resistor.
The DMX lamp is the green led, next to the DMX-selectors.
Glows constant, when the DMX connection is correct.
Flash if the DMX signal is missing or wrongly connected.
