What is the 3-digit code that identifies an instrument and/or its functions in a DMX 512 system?

• A. The address
• B. The serial number
• C. The firmware version
• D. The model number

Answer: (A)

The starting channel used by a fixture inside the DMX512 data stream is the key idea. In DMX, each instrument listens to a specific starting channel in a 512-channel universe, and then uses a set of consecutive channels to control its various functions (like dimming, color, movement, etc.). This starting channel is the address, and it is commonly shown as a 3-digit number (001 to 512) on controllers and fixtures. By assigning a unique address to each fixture, you map the incoming DMX data to the right device and its controls; two fixtures with the same address would respond to the same data, which is usually not desired.

The other options don’t set or identify which channels control a fixture’s functions. A serial number is hardware identification, a firmware version is software, and a model number is product identity. They don’t determine how the DMX data maps to the fixture’s functions.