Realization of Programmable Sequence Controllers Using Semiconductor Read-Only Memories

A systematic approach to the realization of programmable sequence controllers which control the initiations of various functional operations in a plant is presented. The method is based on a partitioning of the sequence of operations into blocks such that no block contains an individual operation more than once. A formal method to obtain the partition blocks is developed. When read-only memories are used to store the sequence, a considerable reduction in storage capacity can be achieved by the method presented.