What does the future hold for virtual instrumentation? Well, you can bet that it is tightly coupled with PC technology.

Getting More Connected
Virtual instruments will continue to displace stand-alone systems, but for new reasons. Previously, scientists and engineers chose virtual instruments because they were less expensive than benchtop instruments and they let them leverage their PC hardware and software. Virtual instruments are now replacing benchtop instruments because they are better connected to such PC technology as powerful display features, processing power, analysis capabilities, and remote control (including over the Internet). Much as word processors delivered new levels of productivity and flexibility to those who previously used typewriters, systems that use virtual instrumentation are proving to be much more capable than their stand-alone counterparts.

For example, have you ever tried connecting a digital multimeter (DMM) to the Internet? It is no simple task. However, with a PC-based virtual multimeter (VMM), you can move acquired data directly into computer memory and transfer it over the Internet. The VMM delivers the specifications you would expect from a DMM but marries them with the flexibility inherent in virtual instrumentation. The VMM is an example of the evolution of virtual instrumentation-connecting multimeters to PCs, replacing general I/O functionality with plug-in DA hardware, and moving traditional instrumentation inside the computer. (See Photo 1.)

Photo 1. Virtual instruments will continue to replace their benchtop counterparts because they offer new capabilities that benchtop instruments cannot match.

New Applications
Virtual instrumentation cut its teeth in the laboratory on Macintosh computers. Users recognized its flexibility and applied it to test and measurement.

High-speed buses, such as PCI and VXI, make virtual instrumentation a powerful tool for such applications as telecommunications, semiconductor manufacturing, and automotive testing. These buses deliver data throughput that can keep up with the performance of high-end processors-in effect eliminating the data throughput bottleneck found in ISA-based configurations. With PCI and VXI, the PC can move data, as well as process it, at high speeds. The PC is now making a strong push into industrial automation applications. From acquiring data to controlling tests to monitoring and controlling processes on the factory floor, improvements in PC technology and virtual instrumentation hardware and software make new applications possible.

One example of the success of virtual instrumentation can be seen at National Instrumentation and Engineering, Inc. The company is using plug-in DA hardware and LabVIEW software in a virtual instrumentation system that improves the in-vehicle data acquisition and recording system used in testing Ford prototypes. The system, operating in triple-digit temperatures during 12- to14-hour days in Yucca, Arizonia, replaces a clutter of display units, gauges, strip chart recorders, data loggers, and engine calibration equipment. The virtual instrumentation system reduces the time required to analyze and process acquired data and increases test safety.

Added Benefits
The benefits of time savings and reduced costs that virtual instrumentation brings to individual divisions of an organization will not go unnoticed by others in the organization. The improved productivity of one group-for example, R&D-will naturally lead other departments to realize the same benefits.

A bit of investigation reveals that the reuse of code is another benefit of virtual instrumentation. Engineers and technicians in testing and manufacturing can adapt much of the code developed by R&D departments. This capability improves productivity across the functional boundaries within an organization.

Virtual instruments are not only reusable from one department to another but are also scalable across hardware architectures. With virtual instrumentation, users can move applications seamlessly between several bus architectures, such as PC Card, plug-in DA hardware, and VXI. This portability offers the flexibility to take advantage of improved bus standards as they arise. With virtual instrumentation, users need not jettison previous work-they can merely migrate to the bus of choice as the need or opportunity arises.

Easier to Build
As virtual instrumentation expands into new applications, vendors must supply tools that will get new users up and running quickly, as well as speed complex system development for more advanced users. The traditional tradeoff here has been one of flexibility vs. ease of use, but through such tools as wizards, the two need not be mutually exclusive.

Virtual instrumentation vendors can look to software products in other industries for solutions. Wizards in more mainstream application software packages quiz users via pop-up dialogue boxes to step novice users through a task. For example, the wizard for building a chart in Microsoft Excel confirms the cells containing the information for the chart, helps users select the appropriate chart type, formats the chart, and adds a legend and labels for axes. Even users who have built charts in Excel for years use the wizard because it is a useful tool for completing the task.

Screen 1. By using Wizard dialogue boxes, LabVIEW users can quickly build data acquisition systems, and experienced users can build customizable prototype systems.

Virtual instrumentation software offers the same tools to help novice system developers get started, while speeding system development for more experienced users. For example, LabVIEW 4.1's DAQ Wizards use point-and-click dialogue boxes for describing measurement connections (see Screen 1), and LabVIEW generates a ready-to-run program that meets these specifications. Users select from lists of common options, such as analog input, digital I/O, and file I/O, and LabVIEW then builds an application in G, the native graphical programming language of LabVIEW and BridgeVIEW.

The benefit here is twofold. Novices can step through the dialogue boxes and quickly build a fully functioning DA application. LabVIEW will help define signal types, connections, and transducer equations before building the system. Thus, the learning curve is shortened significantly. More experienced developers can use the DAQ Wizards to prototype a system and then go into the G block diagram to customize as necessary.

Summary
The future of virtual instrumentation is promising. As such companies as Intel and Microsoft continue to usher in new technologies for advanced productivity and connectivity, virtual instrumentation systems-and their users-only stand to benefit.

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