Page 1208 - The Mechatronics Handbook

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The programming language, whether it be C++, Java, Visual BASIC, C, FORTRAN, HAL/s, COBOL,
or something else, provides the capability to code such logical constructs as that having to do with:

• User Interface. Provides a mechanism whereby the ultimate end-user can input, view, manipulate,
and query information contained in an organization’s computer systems. Studies have shown that
productivity increases dramatically when visual user interfaces are provided. Known as GUIs
(graphical user interfaces), each operating system provides its own variation. Some common
graphical standards are Motif for UNIX systems and Microsoft Windows for PC-based systems.
• Model Calculations. Perform the calculations or algorithms (step-by-step procedures for solving a
problem) intended by a program, e.g., process control, payroll calculations, or a Kalman filter.
• Program Control. Exerts control in the form of comparisons, branching, calling other programs,
and iteration to carry out the logic of the program.
• Message Processing. There are several varieties of message processing. Help-message processing is
the construct by which the program responds to requests for help from the end-user. Error-message
processing is the automatic capability of the program to notify and then recover from an error
during input, output, calculations, reporting, communications, etc. And, in object-oriented devel-
opment environments, message processing implies the ability of program objects to pass infor-
mation to other program objects.
• Moving Data. Programs store data in a data structure. Data can be moved between data structures
within a program, moved from an external database or file to an internal data structure or from
user input to a program’s internal data structure. Alternatively, data can be moved from an internal
data structure to a database or even to the user interface of an end-user. Sorting and formatting
are data moving operations used to prepare the data for further operations.
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• Database. A collection of data (objects ) or information about a subject or related subjects, or a
system (for example, an engine in a truck or a personnel department in an organization). A database
can include objects, such as forms and reports or a set of facts about the system (for example,
the information in the personnel department needed about the employees in the company). A
database is organized in such a way so as to be easily accessible to computer users. Its data is a
representation of facts, concepts, or instructions in a manner suitable for processing by computers.
It can be displayed, updated, queried, printed, and reports can be produced from it. A database can
organize data in several ways including in a relational, hierarchical, network, or object-oriented format.
• Data Declaration. It describes data and data structures to a program. An example would be
associating a particular data structure with its type (for example, data about a particular employee
might be of type person).
• Object. A person, place, or thing, which could be physical or abstract. An object contains other
more primitive objects (or data) and a set of operations to manipulate objects (or data). When
brought to life, it knows things (called attributes) and can do things (to change itself or interact
with other objects). For example, in a robotics system a robot object may contain the functions
to move its own armature to the right, while it is coordinating with another robot to transfer yet
another object. Objects can communicate with each other through a communications medium
(e.g., message passing, radio waves, Internet).
• Real-Time. A software system that satisfies critical timing requirements. The correctness of the
software depends on the results of computation, as well as on the time at which the results are
produced. Real-time systems can have varied requirements such as performing a task within a
specific deadline and processing data in connection with another process outside of the computer.
Applications such as transaction processing, avionics, interactive office management, automobile
systems, and video games are examples of real-time systems.

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Data and object are used interchangeably throughout this chapter to define information in a software program.
©2002 CRC Press LLC