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RUSH MH 5 Profile User Manual
Control data link
A DMX 512 data link is required in order to control the fixture via DMX. The
fixture has 3-pin and 5-pin XLR connectors for DMX data input and output.
The number of daisy-chained fixtures is limited by the number of DMX
channels required by the fixtures in relation to the maximum 512 channels
available in one DMX universe. Note that if independent control of a fixture is
required, it must have its own DMX channels. Fixtures that are required to
behave identically can share the same DMX address and channels. To add
more fixtures or groups of fixtures 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. 24
AWG cable is suitable for runs up to 300 meters (1000 ft.). Heavier gauge
cable and/or an amplifier is recommended for longer runs. The pin-out on all
connectors is pin 1 = shield, pin 2 = cold (-), and pin 3 = hot (+). Pins 4 and 5
in the 5-pin XLR connectors are not used in the fixture but are available for
possible additional data signals as required by the DMX512-A standard.
Standard pin-out is pin 4 = data 2 cold (-) and pin 5 = data 2 hot (+).
To split the link into branches, use a splitter such as the Martin 4-Channel
Opto-Isolated RS-485 Splitter/Amplifier. Terminate the link by installing a DMX
termination plug in the output socket of the last fixture. The termination plug,
which is a male XLR plug with a 120 Ohm, 0.25 W 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.
