Methods and apparatus for electrostatically aided atomization and dispensing of coating material. The apparatus includes a power supply for supplying operating potential and a coating dispensing device remote from the power supply. The coating dispensing device includes an input/output (I/O) device. The I/O device includes at least one indicator for selectively indicating a commanded state of the power supply and a fault state of at least one of the power supply and the coating dispensing device. A pair of conductors couple the I/O device to the power supply. Commands are coupled from the I/O device to the power supply. Commanded state information and fault state information are coupled from the power supply to the I/O device.