Software Defined Modular Instruments


By Raghunandan N V, Technical Marketing Engineer, National Instruments.

Over the last 50 years, Oscilloscopes, Analyzers & Meters, whether they are used to make rise time measurement, measure signal period, identify peak-to-peak voltage, perform spectral analysis on high-frequency signals or measure electrical parameters, have proven to be extremely valuable resources for test and measurement. These instruments form the core of a variety of applications ranging from the test benches to smart automated test systems.

With trends of applications & devices growing in complexity and technology convergence, these instruments have evolved quite a bit since their invention by encompassing latest commercial technology to meet the stringent requirements of lowering cost and delivering longer system lifetimes. To test their smart devices, organizations are transitioning from the status quo of rack-and-stack box instruments and closed-architecture automated test equipment to smarter test systems that deliver the ongoing connectivity and problem-solving capability to meet or exceed that of the device(s) under test.

Often, a combination of test equipment such as oscilloscopes, signal or function generators, analyzers & multimeters are required to test modern systems. A traditional approach, involves stacking up stand-alone instruments which are primarily designed as discrete entities and not for system use. While market has a large choice of traditional instruments, correlating data from one instrument to another and performing custom measurements not included in the function list of a traditional instrument, often pose challenges for users. NI’s modular oscilloscopes, analyzers and meters are based on a software-defined virtual instrumentation approach. These modular instruments, share the common components – such as the chassis, display and power supply – across different instrument modules instead of duplicating these components for every instrument function thereby saving on cost, space & providing a customizable test instrument.

NI has designed & developed more 600 modules of the 1500 PXI products available in the market from the PXI Systems Alliance (PXISA). PXISA consists of over 70 T&M vendors making products complaint with the PXI standard. These software-defined modular instruments allow the engineers to design and implement flexible test systems that can be repurposed quickly. PXI instruments provide a wide variety of I/O interfacing capabilities for ranging from DC to millimeter wave, including the industry’s highest resolution digitizer with 24 bits of resolution and the industry’s fastest, most accurate 7½-digit digital multimeter (DMM).