Design Con 2015

Design cycles put pressure on measurement speed

-December 04, 2013

With the constant pressure to bring new product to market comes an increasing demand for instrumentation that can deliver accurate results as fast as possible—without requiring complicated configuration or setup in advance. This new urgency to get more done faster is, to some extent, the result of some changes in who is responsible for test-and-measurement functions today. It's not all electronics test engineers anymore.

Industry studies have recently highlighted significant changes in the test market. These changes include shrinking product design cycles (down by 13 percent over the last three years) and fewer dedicated test engineers with in-depth T&M background. In fact, one in five electrical engineers now working has started his or her career within the last decade. Many engineers are now, for the first time, responsible for testing. At the same time, the profile of the typical instrument user has broadened.

In addition to electrical engineers, users now include a growing number of engineers from other disciplines who need fast access to data but may have limited training in electrical measurement. A growing number of these users have a greater focus on software than on hardware. For these emerging user segments, traditional button-and-command menu interfaces can present significant challenges.

Over the last decade, the proliferation of consumer electronics with high-quality capacitive touchscreens and intuitive operation have led electronics users of all kinds (not just T&M instrument users) to expect that operating modern devices will be virtually self-explanatory, requiring little or no reference to a traditional user manual. For example, a 2013 poll by the Pew Internet & American Life Project reveals that tablet ownership continues to grow rapidly, with a third of all American adults owning a tablet computer. That's almost twice as many as owned one just a year earlier. These and other icon-based tools like smartphones have become so ubiquitous they are fundamentally changing the way we interact with electronics. This will likely have an impact on the instrument selection process by creating a different set of expectations for ease of use, forcing instrument manufacturers to re-envision what they will offer in order to address these new expectations.

New expectations
A recent survey of Keithley instrumentation users and in-depth interviews have revealed several recurring themes related to customers’ concerns and desires about the next generation of instruments:

  • Users want a simplified interface: "Can’t you reduce the number of buttons and menu structures on the front panel?" "I can use a DMM without a manual. I can use a power supply without a manual. Why can’t I use an SMU without a manual?"
  • Users want to speed up the measurement process significantly: "We care about the measurements. Simplify the setup and let me make measurements quickly." "I don’t have time to teach my students how to use the instrument."
  • Users want to be free to focus on their work, rather than on the details of the test or measurement process: "I'm a materials expert, not an SMU or software specialist. I just want to use the instrument and get on with my work."

The designs of the latest generation of source measure unit (SMU) instruments increasingly reflect these emerging concerns and desires. For example, Keithley recently introduced an SMU with a capacitive touchscreen interface (Figure 1). Configuring a measurement takes roughly half as many steps as earlier designs. Setting up a measurement is as easy as touching an on-screen icon.

Figure 1. The next generation of SMU instruments, such as Keithley’s Model 2450 SMU Instrument, is designed to reduce the number of steps required to configure a test and speed the measurement process.

Finding answers faster
In modern instrument design, no single feature or function can ensure greater testing productivity. Achieving a higher speed to answer depends on a combination of factors. For example, consider something as simple as the instrument's menu structure. Unlike cumbersome soft-key architectures—which may force users to go as much as six layers deep to reach the desired selection—new instruments may present a flat menu structure (Figure 2) that lets users reach the set-up panels they need to configure a measurement with no more than two button presses.


Figure 2. When used in combination with a touchscreen interface, a flat menu structure helps users quickly find and access the measurement and display functions they need.

Some SMU instrument users are reluctant to consult a manual when they're confused about what to do next. All too often, that's because the manual has gone missing shortly after the instrument comes out of the box. So, configuring a seemingly simple measurement can turn into an aggravating, time-consuming process. To help users overcome this reluctance, a growing number of instrument designers are incorporating context-sensitive help functions (Figure 3). But, that's not always sufficient to ensure user productivity. An instrument’s design should allow for intuitive operation, so that configuring it is as straightforward as using a digital multimeter or a power supply. The newest touchscreen interfaces make instrument navigation an intuitive experience by representing many functions and parameters graphically, which can reduce the learning curve associated with using a new instrument.


Figure 3. On-board context-sensitive help functions can be invaluable in getting instrument users up to speed quickly by minimizing the need to consult a manual for guidance.

Many test setups involve multiple instruments, so anything that simplifies the integration process can improve on speed to answer. For example, instrument manufacturers are increasingly incorporating embedded instrument control software to simplify instrument connection and test setup. Such controls automatically configure some of the settings necessary to get you started. These applications offer simple, customizable user interfaces, automatic discovery of compatible instruments on a network, and easy communication with instruments connected to an external controller.

Conclusion
The design philosophy underlying new instrument architectures is undeniably changing. As the time available to make decisions based on test and measurement results continues to get tighter, a growing number of users are likely to begin demanding that their instrumentation vendors deliver better speed to answers without the need to compromise measurement integrity to achieve it.

Also See
How Keithley Improved Speed in Source-Measure Units
Scripts automate source-measure units
Source-measure test system: build or buy?
Best-in-Test 2014: Test Support
Sometimes, analog is better
Building Rich, Animated Android User Interfaces (UIs): A Practical Solution for Software Engineers

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