The book describes new methods of development of programmable logic machines (processor) models as principal logic diagrams and is written for the readers who are interested in systems and devices of program and digital control of various objects using programmable logic machines (PLM) built on the basis of more efficient synthesis and programming methods as compared to the existing microprocessors.
The book thoroughly describes the main methods of discrete object control and studies the structures and functional dependencies of new processors integrated in PLM. A comparative study is provided for the main, more simple and efficient principles of processor development in PLM models. Descriptions are given for methods and circuits ensuring dynamic stability of PLM models operation in transient modes.
Finally, for control of various objects, principal logic diagrams are provided (from simple to complex) for new, more efficient models PLM1…PLM7 with different functional possibilities that allow among other things successive (by cycles) implementation of any finite state machine controlling the object. E.g., PLM7 model contains two interconnected processing units, has 92 binary command codes and can successively and (or) parallely calculate logic and arithmetic functions with one-bit and multi-bit binary variables, identify the group they are assigned to, analyse (diagnose) the readings of discrete and digital detectors, compare them to the database, while executing specific logic operations, and produce corrective and control signals; convert successive binary code to parallel and vice versa, implement non-linear algorithms without changing the command execution sequence and so on and so forth. More simple models PLM1…PLM4 implement successive calculation of logic functions (Boolean algebraic functions) with different processing speed. For the first time, processing units of all PLM models are developed using a new quality of triggers which, as the book proves, are capable of combining implementation of several functions in themselves:
- calculation of logic and arithmetic functions using a carry;
- accumulator functions for the data memory and calculation results;
- functions of successive bit shift of binary numbers in the adder.
This significantly reduces the number of logic components in processing units of PLM models, increases the processing speed, simplifies their operating principles and programming processes.
The problem of non-linear algorithm implementation is solved, while maintaining the sequence of program execution due to termination of active program execution at certain points without transition commands. This simplifies PLM block circuits and PLM operation control methods.
A new method has been developed to reduce the number of cycles during the calculation of normal and bracket logic functions and bit-by-bit logic calculation of multi-bit variables without the need to store and use intermediate values of the calculated functions.
Processing units do not have inputs/outputs for address codes (they do in the general PLM diagram), which simplifies their structure, makes the processors architecture open and allows having any number of external blocks.
There is no need in microprogramming and operating systems, which, as compared to the existing microprocessors, simplifies the structure, understanding of the PLM operating principle and programming and ensures clear connection between the commands and the control object operation logic.
Programming of all PLM models is performed by 92 binary codes or commands, each of which is executed within 1 operating cycle of the pulse generator (PG) and has its meaning. This ensures clear connection between the program and the control object operation, which allows the control system developers to create a PLM operation program without involving programming specialists or using programmed equipment. It is known that the main expenses in the development, implementation, operation and modernization of control systems are associated with the involvement of programming and software specialists.
New PLM model processors described in the book have a simple structure and ‘obvious’ programming, which will reduce labor costs, as well as financial and intellectual costs for development, monitoring (inspection), implementation, operation and modernization of control systems of various objects which require implementation of diagnostic processes, logic program guidance and (or) digital control.
The book describes new approaches to processor development and can be used by students and engineers of corresponding disciplines. The material contained in the book allows both individual specialists and professional companies to create more efficient control devices on the basis of new processors, including programmable logic controllers (PLC), which must make this book more attractive.
The book may also be of interest to a general reader who wants to understand what a processor is and how it works.
Operation of processing units in PLM is described using examples of basic external blocks: input block, output block, RAM, etc.