Block diagram

A block diagram (also block diagram or schematic view) is a generally two -dimensional graphical diagram of a mechanical and electrical system or a calculation scheme by means of which the operation of the system can be described. Usually block diagrams are used to provide a higher level of abstraction, thus enabling a better understanding of the function or the relationship of the system.

The name comes from the block diagram generally rectangular drawn elements in such a diagram. However, the form of this functional primitives can be chosen freely and so often come other geometric figures such as circles, triangles or diamonds are used.

Use

Block diagrams are often used to describe hardware or software systems as well as for the representation of procedures and processes. Such representations are common in hardware and software development and dive under a variety of names in the literature. Examples include, inter alia, almost all UML diagrams.

In addition, block diagrams often come as a possible form of modeling a domain -specific language for the application. In these cases there is often also an automatic transformation of the graphic representation in the form of a code ( for example, C code).

An equally widespread form of block diagrams block diagrams. This special form of a block diagram is used in the electrical / electronics to electrical / electronic systems and interconnections map.

Elements

In general, a block is always the graphical representation of a concrete element from the underlying system or the defined domain with a defined syntactic and / or semantic meaning. In addition, there are also graphical auxiliary blocks ( eg frame or array elements ) as well as textual comments which are mostly used for structuring, but have no semantic or syntactic significance in the system or the domain language.

For software development, for example, describes a block data item, an operator, or a flow control element. Most complex functions ( such as classes in the sense of software development) are represented by a simple block. In the hardware development blocks represent mostly represent simple electronic elements such as AND / OR gates or complex functions, such as the arithmetic logic unit ( ALU) of a processor in the electrical describe blocks most circuit elements such as light bulbs, switches or fuses.

Data, control flow or other contextual relationships are modeled by connecting blocks using lines in the block diagram. The compounds can have various shapes. Here come freehand drawings, arches oblique lines or only horizontal and / or vertical lines (also known as Manhattan routing ) are used. The compounds are usually directed, so have a semantic beginning and an end semantic.

Function block

Function blocks as part of a (functional ) block diagram are used for graphical presentation of technical procedures, processes and contexts. Function blocks contain textual descriptions or brief explanations, small graphics or more nested function blocks can contain. The individual blocks are connected by single-or double-sided arrows that represent the interfaces and flow direction of the exchanged information between the blocks. The two essential features of a function block are therefore its technical function (block content ) as well as the function of the interface ( interface ) to the adjacent function blocks. Functional block diagrams allow the presentation of complex technical processes as simple design overview. The individual functional blocks can be expanded in a further block diagram and broken down into further sub- functions ( top-down approach).

Applications

Block diagrams are usually used when the visualization of data and / or control flow or time / substantive procedures are important. So complex control algorithms are often presented graphically, or data flow or communication between individual components (components) mapped a large system. In this as in many other cases, the graphical representation for humans is usually easier to understand and follow than a textual representation.

An important aspect of block diagrams is often fully automated transformation of the graphical specification in a different specification form (eg C code, Java code, or other chart forms ) or the automatic generation of chip layouts from graphic descriptions.