Get in touch with the changing user interface of today’s test instruments – part 1
Have you noticed the significant changes within the electrical test and measurement industry – not just to the instruments, but among the user community? Perhaps you’re among the one in five electrical engineers who entered the profession within the last decade. Or, maybe you’re not an EE but rather in materials engineering, electrochemistry, biotechnology, physics, etc., but you’re still expected to configure electrical measurements from time to time. Perhaps you have experienced budget or staffing cuts and are under pressure to do more with fewer resources than in the past. These dynamics are further compounded by growing time-to-market pressures as design cycles continue to shrink. With all of these changes, wouldn’t it be great if the test instruments themselves could empower users to learn fast, work smarter, and invent easier?
Figure 1. The typical electrical test and measurements user profile has changed significantly over the last decade.
The last half-century has seen continuous improvements to the user interfaces that instruments provide, as well as the emergence of new features and capabilities. But, until relatively recently, interacting with instruments was typically anything but a seamless process. “Taking data” often required manually transcribing readings from an analog dial or using a ruler to measure traces from a strip chart recorder printout.
Figure 2. Instruments with early analog interfaces often required taking data manually.
Light-emitting diode (LED) and liquid crystal display (LCD) digital readout displays and push-button control interfaces represented the first substantial interface innovations for on-instrument measurement configuration. This interface and display approach helped to simplify the control menu structure and bring more of the menu structure to the top level of the display. The first communications interfaces, including RS-232, GPIB, etc., were soon added to instruments to support system integration and triggering, remote programming and control, as well as transfer of data to external controllers for analysis and display.
Figure 3. Digital multimeters with LED and LCD digital displays and pushbutton controls.
In the 1990s, users began to demand further detail on their measurements, such as the level of current being sourced to the device under test, voltage limits, error messages, etc. This demand eventually led vendors to begin developing brighter, easier-to-read, multi-line vacuum fluorescent displays that could display multiple measurements simultaneously from a single measurement connection. This new display capability also made it possible to present measurements results in more intuitive ways, such as presenting measurement data in a bar graph. To allow users to configure the display settings and performance options, vendors often assigned multiple functions and performance options to the same front panel button.
Figure 4. Instruments with multi-line display and user-configurable functions offer more information with measurement results.
Table 1 offers an overview of some of the most commonly employed instrument interface types and how well they meet various usability requirements.
The good news is that, within the last few years, a growing number of vendors have begun getting serious about taking evolving user characteristics and expectations into account in their interface designs. Some of the more modern electrical test instrument interfaces are beginning to incorporate the concept of “faster time to answer,” such as by offering instruments with web-based interfaces. In fact, some of Keithley’s instruments already feature easy-to-use, powerful, web-based plug & play test software that make it possible to perform tests through any browser, on any PC, from anywhere in the world. These unique, browser- based user interfaces provide a significant boost in productivity. All that’s necessary is to connect the instrument to the Internet via the supplied LAN cable, open any browser and type in the instrument I.P. address, and begin testing.
Figure 5. Innovative instruments with web-based user interfaces support substantial improvements in test productivity.
Touchscreens represent the next step in the “faster time to answer” progression. Consumer electronics like tablets, smartphones, and cameras already exploit the usability advantages inherent in touchscreen technology. The “see it, touch it, do it” quality of touchscreens not only makes these products fun to use but has made them more accessible to those who might otherwise be hesitant to try them. Touchscreens support faster, more intuitive learning than other control and display approaches. And, because their operation is so intuitive, touchscreens can also give users more confidence in what they’re doing, drastically reducing user learning curves and training requirements while improving accuracy and efficiency. It’s hard to argue with the evidence that touchscreens have made consumer products easier to explore and operate. Fortunately, they are equally applicable to test instrumentation.
Figure 6. Consumer products like tablets, smartphones, and cameras with gestural multi-touch interfaces are playing a role in the evolution of test instrument interfaces.
The proliferation of easy-to-use, gestural multi-touch interfaces is driving test instrument manufacturers to develop products that incorporate this same intuitive operation and instant access to information. Keithley has developed a next-generation test instrument that uses an advanced capacitive touchscreen with multi-point, pan-pinch-zoom-swipe operation to bring testing right to the user’s fingertips. This Touch, Test, Invent design, now available in Keithley’s Model 2450 SourceMeter Source Measure Unit (SMU) Instrument (Figure 7), offers a simplified user interface that speeds up the measurement process by helping users test accurately and get results quickly, and allows them to focus on their next breakthrough rather than on learning how to configure the instrument.
Figure 7. Keithley’s Model 2450 is the world’s first touchscreen SMU Instrument with capacitive touchscreen with multi-point, pan-pinch-zoom-swipe operation.
With the Model 2450, operators at all levels of testing sophistication can become expert users practically from the first touch because its intuitive design is highly “learnable.” On-board, context-sensitive help eliminates the need to consult a user manual to get the instrument up and running and minimizes the need to consult a manual during use. With simplified setups configured from the front panel, the Model 2450 supports faster time to measurement and drastic improvements in test productivity.
Figure 8. The icon-based, flat menu structure that Keithley’s Model 2450 SourceMeter SMU Instrument offers can reduce the number of configuration steps to half the number typically required by eliminating cumbersome, multi-level menu trees.
Simplifying the user experience
Some may question whether this new instrument interface approach is for everyone or only for novice or infrequent users. After all, they might reason, some experienced instrument users might be hesitant to adopt touchscreen technology because they’re accustomed to working with front panels with buttons, keys, and knobs and need the tactile feedback that pressing a button or turning a knob provides. However, what’s important to remember is that the addition of a touchscreen to the interface doesn’t rule out incorporating buttons and knobs as needed. The touchscreen can display results using larger, more legible numerals, provide more details about the measurement, or offer graphing capabilities, which earlier single- or dual-line VFD displays couldn’t provide. Also, because touchscreen displays are software defined, they are easily changed to reflect the different controls and indicators required for different applications, freeing up valuable “real estate” on the instrument’s front panel. The intuitive, highly learnable nature of touchscreen-based interfaces can also drastically reduce training time, increase operator accuracy, and improve overall operational efficiencies, which helps drive down the cost to own.