Logic code transformation and minimization algorithm for fault diagnostic systems

Modern paper winders have hundreds of actuators and thousands of lines of programmable logic controller code. The complex structure of winder and its control software requires also new kinds of diagnostic methods. With modern fault diagnostic systems, the operator can quickly and accurately identify the cause of a fault. Building up a fault diagnostic system requires usually a lot of manual work. In this paper are introduced a new multilevel product-of-sums net model and a new level-to-level-minimization algorithm, which enables to automatically transform, minimize and present programmable logic controller programs in fault diagnostic systems.