instruments, the programmer must first learn the device-specific commands found in the instrument's user manual. All analysis and presentation code must also be developed by the programmer. The final program is then interfaced to the driver in one of two ways. The driver can be an object code library that is directly linked to the application program, or it can be loaded into an operating system and accessed through a language's standard I/O functions or through an interface linked to the application program. Application software. Application software makes the complete application development process easier and less time consuming. The software is designed with the novice in mind. When using driver software, only the data transfer (I/O) requirements of an application are satisfied. All the rest of the application development, such as statistical analysis or logarithmic plots, is left for the programmer. Application software, however, makes it easy to handle all the requirements of an application from data transfer to data analysis, presentation, and management. The complete requirements of a typical application program are shown in Figure 5. Unlike a programming language, application software is designed specifically for data acquisition and instrument control applications. Development time is significantly reduced by an easy-to-use, powerful development editor and debugging tools. With these development tools, the user creates a complete application using a consistent development procedure. This procedure varies for each application software package, but each package re-
Data capture and control
GPIB RS-232 Plug-in DAQ
moves the complexities of application programming because the programmer does not have to learn the driver functions or device-specific commands. In addition, the programmer does not have to develop analysis and presentation routines; these are built into the package. Instrument modules. One of the hardest tasks of developing a program that controls RS-232 and/or IEEE-488 instruments is learning the specific programming commands of each instrument in a particular laboratory system. Currently there is no standard instrument language. Each instrument has its own set of commands and its own way of formatting data. Learning how to program any instrument takes a great deal of time. Most application software makes programming instruments easier by supplying validated software routines that control specific instruments. These instrument modules eliminate the need to learn devicespecific commands and also automatically format the data returned from the instrument. Complete language application software. One type of application software is a complete language with a development editor and tools designed especially for data acquisition and instrument control applications that also has all the functionality of a traditional language. High-level, easy-to-use functions for plug-in DAQ boards, RS-232, and IEEE-488 instrument control, data analysis, and data presentation as well as editing and debugging features are available within a powerful, easyto-use program development environment. Initially, the user has to learn the operation of the software package, but
Data
analysts and
Data presentation
formatting
and management
Signal processing Statistics Curve fitting Formatting
Graphics Multiplots
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File I/O Displays Data logging
Driver software
Application software
Figure 5. Application software facilitates the development of a complete application program. The software has built-in routines to handle data capture and control, data analysis (e.g., statistics or curve fitting), and data presentation (e.g., graphs).
ANALYTICAL CHEMISTRY, VOL. 62, NO. 9, MAY 1, 1990 · 571 A