Scalable, Masterless, Distributed, and Redundant Motor Control for PLC Using Object Orientation and Recursivity

Modern Programmable Logic Controllers (PLC) programming tools support object-oriented programming and pointers. In this paper, we show how it is possible to link any number of motor controllers like a chain and obtain a unified interface with redundancy but without using a master. The main principle is twofold, encapsulate existing and well-proven function blocks within other function blocks with added support for pointers and actions (methods). Then add one manager function block for each function block and link these manager function blocks to each other to create a chain. The first manager has no predecessor, and the last has no successor. Status information will flow upward to the first manager, and commands will flow toward the last manager.