Data Network Requirements; Tips For Reliable Data Transmission - Martin ERA 300 Profile User Manual

Data network requirements

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.
Up to 32 devices can be linked together on a single daisy chain. The total number of fixtures in one
512-channel DMX universe is limited by the number of DMX channels required by the fixtures.
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 limits are reached, add another DMX
universe or split the daisy-chained link into branches using a powered DMX splitter.

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 a DMX buffer is recommended for longer runs. The pin-out
on all connectors is:
• pin 1 = shield
• pin 2 = cold (-)
• 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 an opto-isolated splitter such as the Martin™ DMX 5.3 Splitter.
Do not split the link by connecting to both the 3-pin and 5-pin output sockets as this may cause
data errors. 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 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.
Connecting the data link
To connect the fixture to data:
12 Martin ERA 300 Profile user guide