Taking Your Modular Instrumentation Platform to the Next Level of Customization
For many years, the basic model of instrumentation has remained largely unchanged, as engineers and scientists who want to make measurements first purchase fixed-function hardware from test and measurement suppliers.Then they use software, such as NI LabVIEW, on a standard desktop PC to extend the hardware’s functionality with signal processing, decision making, automation, and so on.
Despite the increased flexibility introduced by modular instrumentation, such as PXI and VXI, the functionality of modular and standalone instruments still remained defined in the embedded firmware by the vendor, with no means for you to change this firmware to suit your specific application, until now.
Software-designed instrumentation, such as the new NI PXIe-5644R RF Vector Signal Transceiver (VST), allows you to now create the most flexible, customizable test instruments you can imagine.Using the PXIe-5644R VST, for instance, you can create hundreds of customized RF instruments from a single device.
Figure 1: The FPGA based Software designed instruments such as the Vector Signal Transceiver gives users all of the customization that they needed.
Generally, software-designed instruments feature three defining characteristics:
- Instrumentation hardware designed with open-source firmware based on FPGAs with out-of-the-box capabilities and rich sample code
- Well-built, system design software to abstract the complexity of designing a custom hardware instrument
- A fundamental change in mindset from integrating a fixed-function device to designing exactly the instrument you need
Open-Source Hardware
Based on industry-leading FPGA technology and the principle of open-source software and firmware written in intuitive system design software, such as NI LabVIEW, software-designed instrumentation pushes your software as close as possible to the point where your signal is converted to bits.James Truchard, CEO and cofounder of National Instruments, often calls this LabVIEW-to-the-pin.
By replacing fixed, vendor-defined hardware with a flexible, software-designed approach, you’re free to design exactly the instrument functionality you need.In other words, with a software-designed approach, you no longer have to ask how you make this box do what the vendor intended.Instead, you can start asking if you can make this instrument do what you want, what youwill do, and how you will do it.
System Design Software
Designing a new world of software-designed instrumentation requires well-built system design software to abstract the complexity of designing a custom hardware instrument.The software should first give you a way to design the software in the instrument at a system level, simplifying the complexity of the instrument into basic blocks for visualization and programming.
Then the software should abstract the complexity of the software and firmware of a software-designed instrument at a fundamental level so you can quickly understand the signal flow and know when and how to make additions and modifications.This helps you dig into each abstraction in a hierarchical way to access every function in the instrument.
The software should also be written in a language that can target both microprocessors and FPGAs so you can implement custom functionality in either location to use the inherent parallelism of these two processor architectures.Finally, the software should provide well-written reference designs that help users familiar with more traditional instruments get immediate measurement results.
LabVIEW is uniquely suited to each of these requirements and is the fundamental software used by National Instruments in the release of the first software-designed instruments.Field-proven LabVIEW has been used to program real-time systems for more than a decade and to program FPGAs directly since 2003.
NI LabVIEW 2012 and later provides new templates and sample projects for most NI hardware devices, including the new software-designed RF VST instrument.All of the projects are completely open source and include documentation that clearly shows how they work and the best practices for adding or modifying functionality.
A New Way To Think
After years of learning to program vendor-defined instruments, you can now use the NI PXIe-5644R VST and LabVIEW to design your instrumentation.Early access VST users were customizing their devices in applications such as:
- Embedded protocols inside the instrument to build protocol-aware RF testers
- Integrated, real-time channel models to emulate RF device testing in the field
- Hardware-in-the-loop (HIL) techniques to serve the nonlinearity of RF power amplifiers
- Software-defined radios (SDR) to prototype future RF standards
For some, the applications and potential are obvious.Others will take a while to embrace this new approach.It’s similar to the advance of user-empowered smartphones.Looking back, you cannot imagine life without the diversity of applications solved through this single device.But when the first smartphone came to market, most of the world still viewed it as a simple telephone.How will your perceptions of instrumentation change once software-designed instruments become mainstream?
About Author
Avichal Kulshrestha is a Staff Technical Marketing Engineer at National Instruments. He is a member of IEEE and has years of experience in the areas of RF, wireless communications, and signal processing. Avichal has published multiple technical papers and tutorial articles in various journals.
