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The major application areas for T&M equipment are:
1. Communications: Cellular tests, wireless and wire-line tests, and optical tests
2. Aerospace and defence: Electronic warfare, radar, satellite test and signal monitoring/intelligence
3. Research and development: Digital, radio frequency (RF), microwave, etc
4. Manufacturing: In-circuit tests, functional/automated manufacturing tests
5. Security: Surveillance, military communications
6. Core electronics: Data acquisition, control, automation, semiconductor/component test, nanotechnology, RF and microwave
One of the most challenging applications is in the strategic electronics sector comprising military and aerospace electronics. The reliability and repeatability needs of these markets are unmatched as the margin for errors is minimal.
Technological advancements that have a far-reaching impact on the way T&M is being utilised today include:
1. Faster and smaller semiconductor chips
2. Better and brighter displays
3. Convergence or consolidation
Not only have these advancements helped bring down the test-times and cost of T&M instruments—making them faster and affordable—these have also helped in making them easy to use and more efficient. These advancements have triggered T&M to drive the following key customer needs:
1. Take complexity out of test and save time to focus on where it matters the most
2. Provide reliability and repeatability—the key expectations from any test platform today
3. Offer new alternatives for testing, like instruments with multiple capabilities and automated test set-ups
—Arun Dogra, country manager & VP (sales, marketing & support), Agilent Technologies India
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Demand for more flexible test systems
With recent improvements in embedded systems technology and software engineering, it is now possible to greatly influence a device’s functionality by just changing the software embedded in it. Software-defined functionality is generally more flexible and scalable, and makes it possible to change the characteristics of devices quite rapidly.
This puts test engineers in a fix because traditional test instruments cannot keep pace with the changes in the device-under-test (DUT) because of their fixed user interfaces and hard-coded functions, which are difficult to change. Hence test engineers are also turning to techniques like software-defined and field-programmable gate array (FPGA)-enabled instrumentation, so they can quickly customise their equipment to meet specific application needs and integrate testing directly into the design process.
Software-based instrumentation comes at two levels—virtual and synthetic. Virtual instrumentation is a combination of software and modular hardware instruments that can be customised by the users for their specific needs. It has been used for over two decades but became very popular in the last few years.
“Almost all of the testing industry has accepted the concept of virtual instrumentation, which equals or exceeds traditional instruments in terms of data rate, flexibility and scalability, with reduced system cost,” says Dr Agrawal.
In virtual instrumentation, the software is very powerful—to the extent that it can transform common hardware components into test instruments. For example, an analogue-to-digital converter can be made to function as a virtual oscilloscope. So a combination of common hardware and modular test instruments can be strung together with powerful software to make a test system with completely user-defined functionality. And this can be changed any number of times to cater to the changes in the DUT.
A synthetic instrument on the other hand is purely software-defined. It performs a specific synthesis, analysis, or measurement function on completely generic, measurement-agnostic hardware. So it is a system that can run completely on a PC, without even needing basic and modular T&M instruments. Another recent trend is the use of highly modular and reusable software code, which increases the flexibility of software-based instrumentation solutions even more.
The need for flexibility has also resulted in the greater use of FPGAs in test devices. There are lots of system-level tools for FPGAs these days, so modular instruments with FPGAs can easily be reprogrammed by engineers according to their needs. In fact, with modern software tools engineers can rapidly configure FPGAs without even writing low-level VHDL code!
Meeting the needs of the wireless world
The emergence and popularity of new, high-speed wireless technologies is greatly influencing changes in the test industry.
The high speed requirement of wireless devices and applications has resulted in wireless networks with more spectrum, greater data throughput, technologies such as orthogonal frequency-division multiple access, and advanced antennae with technologies like multiple-input multiple-output and beam-forming. Testing plays a huge role in making all these new technologies work together.
Today’s wireless test equipment have to cover higher bandwidths and many parts of the spectrum. The solutions need to look beyond the channel frequencies specified for the DUT to help detect and minimise RF interference. They also need to take into consideration the security requirements of wireless devices, not to forget their physical robustness and even weather-resistance.
What is more, since the high-speed wireless industry is rapidly growing with new devices and protocols emerging everyday, the test solutions need to be very flexible and customisable. Hence these solutions often comprise standards-based software that can be downloaded to hardware instrumentation and modular platforms—to quickly put together a test system that meets the specific requirements of the project. The solutions must also be simple and foolproof because these might be used by design and field repair engineers with relatively little experience. Plus, since many wireless technologies are meant for low-cost devices, the test solutions must enable manufacturers to verify performance without increasing end-system cost.
Reducing time and costs
“The primary focus of test instrument manufacturers is to accurately capture a signal or create a stimulus. However, demands for lower costs equally drive these specifications in order to shortened tests and hence lower its cost,” says Stasonis.
Indeed, in today’s dynamic marketplace there is a great pressure on manufacturers to introduce new models at short intervals. Consequently, there is a pressure on test engineers to come up with solutions that reduce the testing time and cost while improving the effectiveness of the testing process. This is often achieved by test systems that feature faster signal capture, faster data transfer to the PC for analysis, and more intelligent drivers to shorten development times and minimise test steps.
Cost is as important as speed, because the cost of the test process influences the cost of the device as well. The emergence of flexible test systems that use smart software, modular hardware, FPGAs, etc has had a significant impact on the cost of the test process, as the same solution can be used to test multiple devices.
Another technology that has gained popularity in this context is the built-in self-test (BIST), where a device or machinery is also empowered with the ability to test itself.
“Test departments are constantly under pressure to reduce costs, and with less and less test-point access, BIST can be critical for efficient test,” says Stasonis. Despite the reduced cost and time for testing, BIST is very reliable and is often used in critical spaces such as avionics and defence.
Sagar Patankar, senior program manager, KPIT Cummins, says that test accelerators used in software testing also help meet these time and cost requirements. “Test accelerators are built with three goals: high quality, reduce time-to-market and cost savings,” he says. Some of KPIT Cummins’ innovations in this space include test case optimisation techniques, testing process redesign for software testing and script-less automation testing.
