Patent ID: 7860110

Claim:
An apparatus comprising: a network interface having a plurality of nodes, each node capable of connection to at least one I/O module, each I/O module automatically obtaining a node ID of said each I/O module based on a relative physical location of said each I/O module to other I/O modules using an auto-addressing protocol without using a unique marker of said each I/O module; an installed I/O module operatively connected to the network interface, the installed I/O module comparing an address value contained in a data field and selecting the node ID using a definitively known first available node ID that is greater than or equal to the address value, the installed I/O module modifying the data field to indicate its selected node ID for a next I/O module; and, wherein the auto-addressing protocol provides for automatically determining the node ID of the installed I/O module and skipping a node ID of an uninstalled I/O module.