A stack light with a function generator, the stack light being of the type providing a set of beacon modules interlocking to each other and to a base unit by means of interlocking mechanical connectors and interfitting electrical connectors positioned at a top and bottom of each beacon module and at a top of the base unit together allowing multiple beacon modules and one base to be mechanically and electrically assembled into a tower with electrical communication between the base and each beacon module, the function generator comprising: a housing ; first and second mechanical connectors positioned at a top and bottom of the housing adapted to releasably interlock with corresponding mechanical connectors of beacon modules and a base; first and second electrical connectors positioned at a top and bottom of the housing adapted to releasably interface with corresponding electrical connectors of beacon modules and a base, wherein the first and second electrical connectors each include a plurality of signal lines for providing multiple signal voltages for control of said beacon modules; a power conversion circuit adapted to receive electrical power from one of the connectors to convert said electrical power into a backbone voltage on a backbone power conductor and backbone common for use with the set of beacon modules and for providing backbone power to a function generation circuit ; and said function generation circuit positioned within the housing, wherein said function generation circuit is configured to: receive said backbone power, via the backbone power conductor and backbone common , from the power conversion circuit from the second electrical connector, receive said multiple signal voltages for control of said beacon modules, generate a time-modulated signal, synchronized with the received signal voltages, for control of said beacon modules, and provide each time-modulated signal to the first electrical connector. a housing ; first and second mechanical connectors positioned at a top and bottom of the housing adapted to releasably interlock with corresponding mechanical connectors of beacon modules and a base; first and second electrical connectors positioned at a top and bottom of the housing adapted to releasably interface with corresponding electrical connectors of beacon modules and a base, wherein the first and second electrical connectors each include a plurality of signal lines for providing multiple signal voltages for control of said beacon modules; a power conversion circuit adapted to receive electrical power from one of the connectors to convert said electrical power into a backbone voltage on a backbone power conductor and backbone common for use with the set of beacon modules and for providing backbone power to a function generation circuit ; and said function generation circuit positioned within the housing, wherein said function generation circuit is configured to: receive said backbone power, via the backbone power conductor and backbone common , from the power conversion circuit from the second electrical connector, receive said multiple signal voltages for control of said beacon modules, generate a time-modulated signal, synchronized with the received signal voltages, for control of said beacon modules, and provide each time-modulated signal to the first electrical connector. receive said backbone power, via the backbone power conductor and backbone common , from the power conversion circuit from the second electrical connector, receive said multiple signal voltages for control of said beacon modules, generate a time-modulated signal, synchronized with the received signal voltages, for control of said beacon modules, and provide each time-modulated signal to the first electrical connector. <EOS>