data-acquisition.us

[daqmaster]

High-quality software is a fundamental key towards creating a usable, high-performance, computer-based data acquisition system. The scope of the software includes the computer operating system (Windows, Mac, Linux, or Unix), the programming language (C, Basic, etc.) for the DAQ board, and any functions provided by the DAQ driver software (which is vendor dependent).

DAQ programming, by design, requires low-level hardware function calls, which could be difficult to debug and develop. Fortunately, application software bundled with sufficient function libraries is available for reducing the burden of code debugging, and they can dramatically curtail lead times for prototype development. For example, National Instruments' LabVIEW application software, which uses graphical-programming methodology, by , is one of the more functional products. It functions in concert with a DAQ driver and provides a user-friendly environment for developing complete instrumentation, acquisition, data analysis, and control applications. The user interface of a LabVIEW program can be "tooled" to visually mimic a control panel of an instrument; ergo, LabVIEW programs are often called a "vi", or "virtual instrument".

LabVIEW can also call or code-in external programs, e.g. Matlab from Mathworks, in order to enhance its analytical capability. Output from LabVIEW can be in a graphical or spreadsheet format. This is handy as it makes LabVIEW results compatible with ubiquitous tools such as Microsoft Excel.

DAQ software has the drawback that it adds another layer of code over DAQ driver software. That is, it will increase the load on the computer CPU, and may thus limit or even worsen the performance of DAQ hardware. In addition, its capabilities are subject to the limitations of the driver software. Thus, for example, if the driver of a particular DAQ hardware component is poorly written, the DAQ application software cannot repair the driver and may not be able to execute all of its intended functions.