A modular, digital LED display system is disclosed. The display system includes a modular framing system and a plurality of interchangeable display modules removably mounted in the modular framing system. Each of the display modules includes a number of light-emitting diodes (LEDs) or LED assemblies, each of which serves as an individual pixel or element of the larger digital display system. Each of the display modules also includes a number of locating or index sensors. These locating or index sensors allow each display module to determine at least whether there is another module immediately adjacent. A controller connected to the plurality of display modules receives data from the display modules, including the data from the locating or index sensors, and determines automatically the configuration of the display and the locations of the individual display modules.