Fault tolerant backplane slot allocation

The invention relates to fault tolerant backplane slot allocation. A method and system for allocating slot addresses for modules in a fault tolerant industrial control system includes a pair of backplane switches on each pedestal. Each backplane switch is configured to communicate between one backplane and a module located on the base and between backplane switches located at adjacent bases. A backboard switch on a base of the library main distributes a base address and a slot address for the backboard switch. A backplane switch on each additional base initiates transmission of a base address request. After the susceptor is assigned its own address, a susceptor address response is sent that includes a slot number and susceptor address for an adjacent susceptor. Each pedestal repeats this process in order along the library such that pedestal addresses are incremented by one and slot addresses are incremented by the number of slots on the pedestal, and new pedestal addresses and slot addresses are passed along