Windows-based data-acquisition software bypasses Windows' message queue

Although users have never seen Windows as a platform for hard-real-time-control applications, tools exist for developing Windows-based applications that run in hard real time (see EDN, Aug 2, 2001, pg 65). However, many of these tools require special computing hardware to offload from the host CPU tasks that require deterministic latency. The host CPU then handles the nondeterministic tasks—most notably, those related to the user interface and to communication via shared networks.

For many real-time-application developers, Data Translation's new Measure Foundry package will eliminate the need for special computing hardware. Developers now have the option of using a $495 software package and computing hardware for developing and implementing hard-real-time-control applications. The user-friendly graphical-programming package uses no text-based code or "wiring" of icons.

The intuitive user interface lets you drag and drop function blocks from graphical panels (menus) onto the desktop. You then open these blocks' property sheets to specify the processing parameters and the sources of the signals to be processed. To document your "programs," you can print out images of the desktop and the various property sheets.

The secret behind the applications' predictable delays is Measure Foundry's use of a patent-pending architecture that the company developed for its other application-development package, Vision Foundry. Both packages bypass Windows' normal message queue, which the company claims is responsible for much of Windows' unpredictable timing. Because Measure Foundry and Vision Foundry share their architecture and their approach to application design, you can easily use the two together to develop applications that involve machine vision and other measurements. In addition, Measure Foundry gives developers considerable real-time computational power, enabling them to design applications that make complex decisions.

Data Translation allows you to freely distribute Measure Foundry applications without paying per-user license fees, and the package incorporates a Distribution Wizard that automates the creation of multiple runtime executables.

Data Translation Inc, 1-508-481-3700, www.datx.com.