Programmable process control computer - uses decoder and cycle control unit with ROM containing working programme to decode main program instructions

摘要

Programmable process control computer has a decoder and cycle control unit and an addressing and selection circuit which selects for each programme step the corresponding instructions depending on data processed in the preceding programme steps. Pref. the decoder and cycle control unit has a read-only memory containing the working program to decode the main program instructions and produce control data for the other operating circuits. The addressing and selction circuit has a working memory with memory elements corresponding in number to the maximum number of instructions, whereby at any given time the state of the working memory reproduces the state of the process cycle.