EDNE October 2012 - (Page 55)

IntroducIng softwaredesIgned InstrumentatIon to test-and-measurement One way tO minimise test and measurement hardware cOsts and reduce test time is tO use virtual, sOftware-defined instruments alOng with mOdular i/O; hOwever, a new apprOach – sOftware-designed instrumentatiOn – gives test engineers the ability tO achieve test time reductiOns that are Orders Of magnitude beyOnd what was previOusly pOssible withOut custOm chip designs and large amOunts Of design investment. By J E rE m y T wa iTs • N aT io N a l iN sT rum ENT s T he number of wireless devices and diversity of protocols increases dramatically each year. With each subsequent generation of technology, the cost of testing wireless devices using traditional techniques has also increased, as more equipment is needed and more sophisticated technology is included in each item. For years, test engineers have taken advantage of software packages to customise and automate measurement systems and reduce cost. Not only does this software-defined approach provide flexibility, it also gives test engineers the ability to take advantage of the performance provided by the latest PC and CPU technology. Nevertheless, for many demanding test applications the performance of the CPU can be a bottleneck. CPUs inherently feature limited parallelism, and typical software stacks result in latencies that can reduce test system performance in cases where measurements need to be adjusted dynamically based on measurement values or device under test (DUT) state. For optimal RF test system performance, custom digital logic is desirable, in combination with multicore CPU technology. This gives test system designers the ability to achieve a balance of low latency and high throughput that can dramatically reduce test times. FpGas’ rolE iN T&m Figure 1: National Instruments’ Vector Signal Transceiver occupies a three-unit module width in a PXI chassis; the product description appeared in EDNE for September, at www.edn-europe.com/article.asp?articleid=5738 Whilst off-the-shelf instrumentation hardware has traditionally been fixed in capability, field-programmable gate array (FPGA) technology offers the possibility of creating more open and flexible measurement devices. FPGAs are high-density digital chips that the user can customise; in the T&M context, they give test engineers the ability to directly incorporate their custom signal processing and control algorithms into measurement hardware. The result is off-the-shelf hardware that incorporates the best of both worlds. On one hand, fixed high-quality measurement technology and the latest digital bus integration: and on the other, user-customisable logic that is highly parallel, www.edn-europe.com OCTOBER 2012 | EDN EuropE 55 http://www.edn-europe.com/article.asp?articleid=5738 http://www.edn-europe.com

Table of Contents for the Digital Edition of EDNE October 2012

Cover
Contents
International Rectifier
Microchip
RS Components
Masthead
Microchip
EDN Comment
Pulse
Analog Devices
Farnell
Baker's best
Omicron
Test & Measurement World
Agilent Technologies
Maxim Integrated Products
Maxim Integrated Products
Digi-Key
Mixed-signal SOC verification using analog behavioral models
Messe München
Bergquist
The future of connected-device security
Silicon Laboratories
Digi-Key
Coilcraft
Messe München
Image sensors evolve to meet emerging embedded vision needs
Digi-Key
Chip Expo
National Instruments
Supply chain
Introducing software-designed instrumentation to test-and-measurement
Digi-Key
Mechatronics in design
Design ideas
Product Roundup
Tales from the cube

EDNE October 2012