A Constructive Method for Resolving Multiple Access Conflicts in Process-Oriented Programs

The problem of increasing the fault tolerance of control software for programmable logic controllers (PLCs) and developed with the process-oriented approach is addressed. Multiple access conflicts that arise in process-oriented programs when implementing mutually exclusive operations on a single executive element are considered. The causes of these conflicts are analyzed, and a modification to the mathematical model of a process-oriented program is proposed to allow for their constructive elimination. On the one hand, the elimination of this class of conflicts increases the fault tolerance of control programs; on the other hand, it has no side effects and thus makes unnecessary any change in the general program structure. The modified model is proposed to be implemented using an extension of the poST language syntax.