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Date: 2021-12-09
Data link
A DMX 512 data link is required in order to control the Roll Down via DMX. The Roll Down has 5-
pin XLR connectors for DMX data input and output. The pin-out on all connectors is pin 1 = shield,
pin 2 = (-), and pin 3 = (+).
Pins 4 and 5 in the 5-pin XLR connectors are not used in normal operation and are available for
possible additional data signals as required by the DMX512-A standard. However, if desired this
additional port may also be used to feedback the actual position of the tube, but in such case, it is
not suitable for daisy chaining.
The Roll Down is subject to the common limit of 32 devices per daisy-chained link. Note that if
independent control of a Roll Down is required, it must have its own DMX channels assigned.
Products that are required to behave identically can share the same DMX channels. To add more
products or groups of products when the above limit is reached, add a DMX universe 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. AWG24 cable is suitable for runs up to 100 meters
(328 ft.).
Never split a DMX line without using an opto-isolated RS-485 splitter/amplifier.
Terminate the link by installing a termination plug in the output socket of the last
Roll Down
. The
termination plug, which is a male XLR plug with a 120 Ohm, 0.25W 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 Roll Down to data:
1.
Connect the DMX data output from the DMX controller to the male 5-pin XLR DMX input
connector (DMX 512 IN).
2.
Connect the DMX output of the products to the DMX input of another product and
continue connecting products output to input (DMX 512 OUT).
3.
Terminate the last product on the link with a 120 Ohm resistor.
The DMX lamp is the green LED, above the display.
−
Glows constantly, when the DMX connection is correct.
−
Flashes if the DMX signal is missing or wrongly connected.
