In accordance with the invention, there is described systems and methods for automatically determining the configuration of a sign display panel. The sign display panel includes a controller electrically connected to a set of display units by an interconnect unit. The interconnect unit includes a set of display unit connection ports for connecting the interconnect unit to a subset of display units. Each of the display unit connection ports includes a sensor for indicating whether the subset of display units is electrically connected to the display unit connection port. The interconnect unit includes software for automatically determining the configuration of the display units.