Method of coupling open systems to a proprietary network

Abstract

An interface provides a path to transfer data from a proprietary network to an open system. The proprietary network includes at least one module central processing unit (CPU) and a module memory associated therewith operatively connected to the proprietary network. A shared memory and shared memory logic are interposed between the proprietary network and the open system, thereby forming the data path. The method comprises the steps of accepting requests for data from the open system by a parasitic task function within the module CPU. The data requested of the proprietary network is obtained and placed in a predetermined location of the module memory in a form understandable to the open systems. A pointer value is placed in the shared memory, the pointer value containing the value of the predetermined location of the module memory, the shared memory being mapped in the addressable memory space of the shared memory logic using virtual memory techniques. The data is obtained directly from the module memory utilizing the pointer value corresponding to the data requested, thereby allowing open systems to access the proprietary system while maintaining the integrity of the proprietary network.