In a computer system having redundant power supplies, an I.sup.2 C data bus architecture it utilized to provide communication between the power supplies and other computer peripherals connected to the I.sup.2 C bus. A switch separates the power supplies from the other peripheral devices, such that the switch, when open, isolates the power supplies from the other devices, so that during power-up the power supplies can communicate over the I.sup.2 C bus. When the switch is closed, the switch becomes transparent and connects the peripherals with the power supplies over the I.sup.2 C bus.