The Model of Data Exchange and Data Storage in Multi-Level Technological Process Control Systems

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The structure of a multilevel process control system (MPCS) with the organization of data exchange via a multiport memory based on a modular principle has been developed in this work. The use of a modular principle enables to effectively organize enhancement and modification of a system designed. The structure of the multilevel system for process control includes three levels: data acquisition and control actuators; supervisory level and process control; operator control and decision-making. The key feature of each MPCS level is its hardware and software components along with the problems to be solved by them. Firstly, the level of data acquisition and control actuators enables performing such functions as data acquisition, data accumulation from the sensors and data processing. This level employs hardware and software tools based on the microcontrollers of STM8 family. Secondly, the supervisory level and process control exhibits data acquisition, accumulation process control data, online data processing, forecasting of a behavior of processes and controlled objects. Data processing of this level reduces the volume of data that have to be transferred to the upper level and thereby lowers bandwidth requirements of communication channels. The hardware and software tools of this level must work in real time. Thirdly, at the level of operator control and decision-making the following tasks are performed: data acquisition, data storage and data processing; processing of video streams, recognition of images and scenes in vision systems; decision-making; synchronization of universal time in a distributed system; synchronization of operation of the distributed subsystems; visualization and representation of the implementation process. In addition, this level contains a SCADA system, the main function of which is to create an operator interface and collect data on process control. As a result of the research requirements for exchanging and storing data were formed, the structure of the device to store and exchange data was designed and multi-port memory controller was synthesized. The method of conflict-free parallel data exchange using multi-port memory was improved by matching the intensity of access to data with the intensity of data flow, which allows determining the necessary performance of the random access memory.