Hardware Reference
In-Depth Information
10 Software packages
It should be self-evident that the effectiveness of any PC-based data acquisition,
instrumentation, or control system will be dependent not only upon the hardware
employed but also upon the software which controls the system. Software has
a vital role to play in that it provides an interface and acts as an intermediary
between the user and the physical components of the system. Furthermore, the
degree of control, flexibility, and ease of use will largely be dependent upon
this software interface.
The newcomer to PC-based instrumentation and control systems can be for-
given for being baffled by the variety and complexity of software packages
designed to assist him in his task. This chapter categorizes software packages
on a variety of grounds and provides details of several of the most popular
software products. The aim has been that of providing a yardstick by which the
control and instrumentation engineer can judge his or her current and future
software requirements.
As an example, a stand-alone process controller may, for example, require
relatively unsophisticated software in the form of a simple 'turnkey' pro-
gram developed in a high-level programming language. A complex distributed
factory instrumentation system, on the other hand, which requires frequent
re-configuration and which may necessitate interfacing with several other appli-
cations programs, may require the services of an applications programming
environment.
Selecting a software
package
Several factors need to be considered when selecting any software package.
These are:
•
Ease of use what level of expertise is required in order to make use of the
package?
•
Flexibility - can the package be easily adapted to differing requirements and
can it be readily interfaced with other software?
•
Performance - what performance criteria and specifications must be met?
•
Functionality - does the package offer a suitable range of functions and will
it interface correctly with the chosen hardware configuration?
To some extent, this last factor is paramount since, if the package cannot
offer support for the particular hardware configuration in question, it may be of
little use. Readers should be aware that a hardware specification will often be
fixed before a full software specification has been developed.
Ease of use
The question of ease of use will largely depend upon the person (or persons)
who will be using the system. In any event, a software package should be
