It's easy to picture the traditional workstation. Simply imagine a high-powered UNIX computer, somewhere between a PC and a minicomputer, that tackles power-hungry applications like computer-aided design/engineering (CAD/CAE), computer-aided manufacturing (CAM), graphics, or publishing. Yet today, even the least expensive PCs can outperform the workstations of just 10 or 15 years ago.
With embedded microprocessors showing up just about everywhere, the term "workstation" takes on a new meaning. For example, musicians may be familiar with Yamaha's Tyros2 Arranger Workstations. These powerful keyboards let performers compose music and "add tracks" without desktop PCs because the PC is built in.
In industrial automation systems, workstations often mean dedicated human-machine interfaces (HMIs) located in the control room, in the engineering department, or on the plant floor. But today's distributed industrial networks are migrating from proprietary to Ethernet TCP/IP.
They let HMIs/workstations collect industrial data from any number of industrial controllers, massage it, and present it to engineers and operators who often have to make split-second decisions. This distributed model can be applied to test and measurement equipment, whether it's located in a test stand or on the design engineer's bench, to provide enterprise-wide information and distributed engineering across the globe.
Some vendors call their scopes and calibrators workstations because they feature embedded PCs. Perhaps digital storage oscilloscopes (DSOs) with an embedded PC—one that lets designers run the software they use on their desktops (e.g., LabView, MS Excel, MS Word, and Microsoft's OneNote notetaking/collaboration program)—qualify as workstations. Maybe your idea of a "workstation" includes the furniture that houses your test equipment.
Regardless of the definition, a few things are clear. Most users clamor for simplicity, ease of use, accuracy, repeatability, and reliability. With PC-based instrumentation, engineers are discovering the benefits of connectivity. They share design data with other engineers and suppliers, as well as measurement data with quality and test groups. While the general-purpose interface bus (GPIB) has served the industry well over the last 20 to 30 years, newer solutions promise more versatile and less expensive connections.
DO WE NEED A DEFINITION?
A few engineers might consider testbench furniture to be a workstation. Perhaps Tektronix's TM500 series of modular test equipment represents a fine example of a bygone workstation. Its modules could be mixed and matched to suit an engineer's needs. This mainframe, pluginbased equipment didn't have any smarts compared to today's microprocessor-based instruments. Yet its modular design was durable, versatile, and elegant in its simplicity.
Does a PC with plug-ins or an extension rack constitute a workstation? Possibly. According to Mike Jaynes, manufacturing engineer at New Star Lasers, today's PC-based plug-ins may display different problems. While they're ideal for production testing where setups can be called with pass/fail limits, they don't have a dedicated instrument's ease of use when the need arises for a quick measurement. Also, not all plug-ins can withstand the measurement of extremely high-voltage signal levels. Jaynes suggests that engineers who tend to work with digital voltage levels may find these PC-cardbased workstations viable.
For Alon Harpaz, electrical engineer at Danaher Motion, the term " workstation" first brings to mind the familiar box-monitor-keyboard-mouse setup. But he acknowledges that the concept can be extended to anything that allows a very flexible control approach and extensive data-manipulation capabilities.
It makes little difference if data plotting and analysis is conducted in MS Excel (or any spreadsheet) or with dedicated packages such as LabView. He further notes that the engineer should be free to explore meaning and information within data sets using appropriate and/or convenient tools. Engineers also shouldn't be limited by the hardware used to acquire the data.
Does "workstation" apply to a PCbased scope? Harpaz suggests that a workstation would allow data-analysis tools to be added. Using " workstations" to describe scopes that use an embedded form of Windows where Windows' functionality isn't directly accessible wouldn't be accurate.
Agilent's Infiniium 8000 series oscilloscopes can use LabView as the user interface to the scope (Fig. 1). In addition, they can run other Windows programs-like Excel or MatLab and programming languages such as MS Visual Studio.
An interesting application for running MatLab on a scope is to use the software as a real-time filter. Dan Monopoli, marketing engineer at LeCroy, says that engineers may have a proprietary algorithm or filter that they need to run before observing the measurement signal.
It's possible to take the data from the scope channel, send it into MatLab, process it in real time, and display its output in real time. Monopoli also notes the obvious advantage—designers don't need a PC on their bench, so they have space for other instruments.
Another advantage to using PCbased scopes and logic analyzers is connectivity (Fig. 2). "Since most of these instruments also have network connectivity, they're easy to configure with the user's PC to take advantage of word processors, spreadsheets, and database applications," says Steve Coan, design engineer at Relcom Inc., a manufacturer of industrial local-area-network (LAN) components.
"The new LabView 8 offering from National Instruments touts distributed applications," Coan continues. "Thus, the definition of workstation is changing and may ultimately depend upon the user's application to define what it really is."
Distributed software applications can help engineers automatically document tests to suit regulatory agencies, eliminating manual data entry. Jaynes' company, New Star Lasers, is an FDA-qualified (CFR Parts 210, 211, and 820) medical device development and manufacturing group specializing in surgical and cardiovascular lasers.
Like many pharmaceutical and food manufacturers, his company must comply with FDA record-keeping requirements. It manually conducts final product test measurements and enters them into a test report.
Electronic record keeping (FDA 21 CFR Part 11), which has become more prevalent in the food and pharmaceutical industries, could replace paper records. But for the most part, test-instrumentation vendors seem unaware of FDA 21 CFR Part 11 and how to implement it.
Fortunately, for those who have access to LabView software on their "workstations," help is on the Web. Log on to to National Instruments' Web site (www.ni.com) and search for "Using LabVIEW to Create FDA 21 CFR 11 Compliant Applications." System integrators and other third parties also are ready to assist.