Programmable sequence controller

摘要

A programmable sequence controller using a technique called microprogramming, including a microprogram memory having a plurality of memory sections each storing a set of microinstructions corresponding to the command word of a sequence instruction. The operation code of the sequence instruction is applied to the upper bits of the microprogram memory so as to select one of the memory sections. The remaining bits are determined by a counter and the ON/OFF state of an I/O element so that one of the microinstructions is read out from the selected memory section.