TABLE OF CONTENTS In today's computer-oriented society, most control modernization projects take advantage of the new and expanding capabilities of microprocessor-based digital control systems [DiDCs, digital distributed control systems, also called distributed control systems (DCSs) and programmable logic controllers (PLCs)]. Because these systems are capable of performing both regulatory and supervisory controls, plant personnel have had to learn how to maintain computer-controlled systems. Because these systems are more software-oriented than hardware-oriented, maintenance of these systems requires a knowledge of software configuration and programming.
Configuration and programming tell a computer how it should sequentially process data to accomplish a given goal. Configuration and programming also define the resultant list of instructions, which a computer interprets to guide its processing actions.
| Tip | A computer term to remember is GIGO, which stands for Garbage In, Garbage Out. This is to remind computer users that the machines are only as useful as the programs people write and the information used in the computers. |
Remember from basic computer courses: The processor reads an instruction from memory. The instruction describes an operation (command) and usually an address to find or put the data used. The set or list of instructions that are created to accomplish some specific objective is called a program. The act of coding, entering, keying, or punching the program into the computer is called programming. The program and, in fact, all of the instructions that command the processor operation are part of the system's software.
To most instrument and control systems engineers, configuration and...
