A system includes a power source and a plurality of modules, where each module has a control for controlling a function of the module and a user input actuatable by a user. The plurality of modules are electrically connected in series with a power conductor electrically connected between each adjacent module, where the power source provides power to each module over the power conductor. In response to actuation by the user of the user input on a select module of the plurality of modules, the control of the select module generates a control signal that is transmitted to each other module over the power conductor, such that the control of each other module controls the associated function in the same manner as the select module.