Industrial automation system and method for efficiently transferring time-sensitive and quality-sensitive data

Abstract

The system and method of industrial automation provides improved network transfer of data between nodes. The system comprises a plurality of computer systems which are interconnected through a network, wherein each of the computer systems executes industrial automation software. One or more of these computer systems interface to various hardware I/O devices for data acquisition. Each computer system is home to one or more client and/or server processes. Before data acquisition begins, every server process registers a plurality of time/quality (TQ) groups, wherein each TQ group is identified by a time/quality identification value (TQID), and wherein each TQ group represents a set of associated data elements. When a hardware I/O device generates data, a server process which is linked to that device through a device driver receives a block of data from the device. The driver assigns to the block a single timestamp and a single quality value. Using a real-time protocol, the server adds one or more blocks of data to a packet and transmits the packet to every client which has subscribed to the data. For increased network and computational efficiency, the real-time protocol includes compression techniques and is exception-based: only changed data elements, changed timestamps, and changed quality values are sent to clients. Both the clients and the server store the TQID for each block, so that the client can more efficiently update the changed timestamps and changed quality values for all data elements in a TQ group.