Data; Tips For Reliable Data Transmission - Martin MAC 550 Profile User Manual

D
ATA
Important! Never connect more than 1 data input and 1 data output.
The MAC 550 Profile has both 3-pin and 5-pin XLR sockets for DMX input and output. The pin-out on all
sockets is pin 1 to shield, pin 2 to cold (-), and pin 3 to hot (+). There is no connection to pins 4 and 5.
The sockets are wired in parallel: both inputs connect to both outputs. For reliable data transmission and to
avoid damage to the fixture, never use more than one input and one output!

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.
• Never use both outputs to split the link. To split the serial link into branches use a splitter such as the
Martin 4-Channel Opto-Isolated RS-485 Splitter/Amplifier.
• Do not overload the link. Up to 32 devices may be connected on a serial link.
• Terminate the link by installing a 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 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.
• Martin fixtures introduced before 1997 have reversed polarity data sockets (pin 2 hot and pin 3 cold). The
socket polarity is labelled. Use a phase-reversing cable between the MAC 550 Profile and any Martin
device with reversed polarity.
To connect the data link
1. Connect the DMX data output from the controller to the MAC 550 Profile's 3-pin or 5-pin input (male)
socket.
2. Using the sockets that match your data cable, connect the output of the fixture closest to the controller to
the input of the next fixture.
3. Insert a male 120 Ω XLR termination plug in the 3-pin or 5-pin output of the last fixture on the link.

Data

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