A computerized power management control system (10) includes a virtual modular relay device (82) for providing input and output data to and from a corresponding, actual modular relay device (47 or 49). Virtual modular relay device (82) is displayed in a window (90), with the upper left-hand corner of window (90) including a graphical depiction (92) of the modular relay device. Immediately below the graphical depiction (92) is a communications status indicator (94), which shows the status of communications (connected/disconnected) between the virtual device (82) and an inter-process communications server (52). Various fields (96) appear along the left-hand side of window to identify the modular relay unit (47 or 49). Below identification fields (96) are a plurality of buttons (98), each of which allow the user to activate a program module. Buttons (156 and 154) can be customized by the user to activate any program module. Tabbed pages (102) allow the user to quickly view numerous functions without cluttering the computer screen. The functions depicted on each of the tabbed pages (102) are user-defined. A program utility automatically configures the virtual modular relay device (82) graphic and links the virtual intelligent electronic device (82) to its actual counterpart (47 or 49) so that input and output signals may be sent between the two.