10
MAC 101 user manual
Data link
A DMX 512 data link is required in order to control a MAC 101 via DMX.
The MAC 101 has 5-pin XLR connectors for DMX data input and output. 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
MAC 101 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 (+).
The MAC 101 is not subject to the limit of 32 devices per daisy-chained link which is common in Martin
fixtures. Instead, the number of fixtures is either limited to 256 or limited by the number of DMX channels
required by the fixtures in relation to the maximum 512 channels available in one DMX universe, whichever
limit is lower. 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 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.
• Never use both a fixture’s outputs to split a DMX link. 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 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.
Connecting the data link
To connect the MAC 101 to data:
1. Connect the DMX data output from the controller to the closest MAC 101’s male 5-pin XLR DMX input
connector.
2. Connect the DMX output of the fixture closest to the controller to the DMX input of the next fixture and
continue connecting fixtures output to input.
3. Terminate the last fixture on the link with a 120 Ohm resistor.
