System and method for assigning addresses to i/o devices in a control

Abstract

A method and system is provided for assigning addresses to input/output (I/O) devices in a control network, and for verifying addresses assigned to the I/O devices. The system comprises a logic controller providing memory into which a connectivity map may be programmed. The connectivity map defines a specific expected address for each I/O device in the system. The logic controller further provides an external controller bus and logic for downloading the connectivity map to an I/O bus manager connected to the logic controller via the external controller bus. The I/O bus manager provides logic for assigning the specific addresses to the I/O devices. Network nodes connect the I/O bus manager to I/O cluster units in the system, each network node including a multiplexer for multiplexing output signals from the I/O bus manager and a demultiplexer for demultiplexing input signals from the I/O cluster units, the multiplexing/demultiplexing functions provided by a controller area network (CAN) integrated circuit. Each I/O cluster unit includes a multiplexer for multiplexing input signals from the I/O devices and a demultiplexer for demultiplexing output signals from its associated network node, the multiplexing/ demultiplexing functions again provided by a controller area network (CAN) integrated circuit. Each I/O cluster unit provides means for manually requesting address assignments and a visual indication of addresses so assigned. Each I/O cluster unit also provides means to manually reject the address assigned to it by the I/O bus manager if the assigned address is not the expected address for the I/O cluster processor defined in the connectivity map.