Programming language instruction code

This is the lowest level of requirements decomposition. The technical design specification deliverable is translated into software source code. Source code is the human readable version of the list of instructions (programs) that enable a computer to perform a task. Source code is written in the programming language appropriate for the application to be generated. 

Programming refers to a set of coded instructions (using various programming languages) that enable a computer or other machine to perform a desired sequence of operations. 

BASIC. It means Beginner s All-purpose Symbolic Instruction Code and was developed by John Kemeny and Thomas Kurtz (1963). Basic is easy to learn and use. It was mainly designed to be used as an interactive language. Almost every computer manufacturer provides, BASIC on its machines. BASIC is probably the most widely used programming language in the world because of the widespread use of microcomputers. 

BASIC (Beginner s All-Purpose Simplified Instruction Code) began as an interactive computer programming language especially easy to learn. Invented in 1964, it now exists in many widely different versions. Students learning programming for the first time may know BASIC as the simple language found on most personal computers. 

BASIC programming language (John Kemeny and Thomas Kurtz) Kemeny and Kurtz develop the BASIC computer programming language. BASIC is an acronym for Beginner s All-purpose Symbolic Instruction Code. 

As per lEC 61131-3, structured text, ladder diagram, FED instruction list, etc. are programming language for PL(2s. FTA is generally performed before codes are generated, and it is done in automatic/semiautomatic mode. There are two kinds of views in looking at software (SW) FTA. These are ... 

In the past, PLC programming languages were limited to simple code (e.g., ladder logic) which is a limited variability language usually having no branching statements. These earlier languages are suitable for use at all SILs with only minor restrictions on the instruction set. 

Figure 3 shows the different phases. The source code is parsed to obtain an abstract syntax tree (AST) associated with the source programming language grammar. Next, a metamodel extractor extracts a simplified, abstract version of the language that ignores all instructions that do not affect the data flows, for instance all control flows such as conditional and loops. 

By electronic engineering, a system of interconnected switching devices is able to respond in one of only two modes (on or off), and these modes can be controlled at the basic level of a bit. Bits are assembled into bytes, as with an 8-bit device, and through programming of the bytes a computer central processor can be made to follow sets of instructions (programs) written in special languages, either at a direct level (machine code) that can be acted upon immediately by a computer or at a high level that is translated for the user into machine code. 

Although much easier to assemble, a software program written in a high-level language requires more time for the computer to execute, since all the instructions must be translated into machine code before the computer can understand them. Even a simple statement like start in a high-level language requires several machine-code moves to execute. 

A solution to avoid all the pain of machine-language or assembler is a series of high-level languages, a "compiler," which translates, much as a dictionary would, these instructions into machine code, and a "linker," which connects parts of the task with each other, with "library" routines such as sin(x), cos(x), random(x), and so on, and with input/output (I/O) calls, to create an executable program. The compilers should allow the same "source" code to be compiled, with minor modifications, on any computer "platform" that supports a compiler for that language. 

The compiler is the primary interface to the processor. High level languages like Fortran and C are translated into the level instructions that can be executed on the processor. Compiler optimization and instruction generation decisions can be influenced with compiler switches. These switches may correspond directly to individual modules for optimization, or influence settings of several modules. The compiler performs many optimizations on the source code based on various assumptions about the program. Typical assumptions are ... 

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