Signature functional control method of the digital automatic devices with programmable logic

Abstract

Today, programmable digital automatic devices have become an integral part of various control, measurement, and control digital devices and systems. Therefore, in the conditions of the cyberattacks spread, the programmable digital automatic devices software becomes one of the most cyber-vulnerable components of modern digital systems for ensuring the operation of critical infrastructure objects. As a result, the problem of finding effective methods for ensuring the efficiency and reliability of monitoring the program's progress at each cycle of addressing the tuple of programmable digital automatic device commands in the real-time scale of their target functioning is becoming more relevant. In the article, based on a critical analysis of the well-known methods of controlling the progress of programs, a method of ensuring the operational controllability of the programmable digital automatic devices is proposed based on the principle of predicting the control signature of the command at each subsequent addressing cycle relative to its previous cycle. At the same time, the possibility of such control for a set of basic (typical) simple structures of addressing algorithms (linear following, branching, and cycle) has been proven as the basis for solving the compositional problem of ensuring the signature controllability of the progress of programs (microprograms) by the method of predicting control signatures for non-elementary addressing algorithms commands. In the context of the practical implementation of the proposed method of signature control, a formulas system of control signature equations (rules of signature functional control) is presented. This makes it possible to implement a new principle of functional control of the digital automatic device — checking automatic device functioning in real-time by introducing unified hardware control redundancy from functionally complete elementary structures of the combinational type. It was determined that the further topic of the article is the development of automated software for the structural synthesis of hardware redundancy (nodes of signature functional control) using the method of predicting signatures for digital automatic devices with «flexible» logic for various purposes. At the same time, the mathematical apparatus of the author's signature Boolean-polynomial algebra is proposed as the basis of structural synthesis.