Protect Your Instrumentation Investment with Software
19 September 2017
For over 50 years, test engineers have been taking a PC-based approach to automating stand-alone instrumentation. With so much investment tied up in capital assets for test equipment, engineers are looking for reassurance that they can satisfy current and future testing needs.
While capital expenditure on hardware is often the easiest cost to associate with test, the importance of a good software investment is commonly overlooked. Instrumentation will continue to evolve, but one thing remains consistent over time—software. Software is at the heart of every instrument control system, and it can help you future proof your application.
Abstracting Instrument Communication with Software Over the past decade, instrumentation systems have evolved and grown more complex. Today’s test systems often mix communication buses and different instruments from a variety of vendors leading to hybrid test systems. The biggest challenge in ensuring long-term operation of hybrid test systems resides at the software layer.
The Virtual Instrumentation Software Architecture (VISA) I/O software specification was developed to help solve the problem of bus and instrument vendor interoperability. VISA provides a common foundation for the development, delivery, and interoperability of high-level multivendor system software components, such as instrument drivers, soft front panels, and application software.
VISA simplifies instrument communication so you can focus on the task at hand rather than the low-level details of a given bus communication protocol. For example, the VISA command to write an ASCII string to a message-based instrument is the same whether the instrument is GPIB, USB, or Ethernet. With NI-VISA driver software, you can add support for a new bus without making changes to your interfaces and use established and emerging multipurpose buses side by side without worrying about breaking your applications.
VISA standards also help users maintain their test apparatus throughout upgrades and OS changes. New OSs are released each year, leaving users with the daunting task of upgrading while maintaining the integrity of the existing test system. The complexity of a system upgrade depends heavily on the software development tool. VISA manages the low-level communication to the OS and the hardware device, so you can freely move to new OSs without changing your application. Finding a software environment that integrates with regularly updated VISA implementations is imperative to protect your instrument control software investment. Software, such as LabVIEW, seamlessly works with VISA, which removes many of the challenges associated with switching to a new OS.
Taking advantage of new PC technologies, such as multicore processers, can yield huge system performance gains. Choosing a software environment that is flexible enough to incorporate cutting-edge technologies can help you stay ahead as your system requirements change.
Instrument Drivers That Stand the Test of Time Instrument drivers give application software the ability to interact with an instrument. Generally, an instrument driver is the preferred approach because it simplifies communication with the device by abstracting low-level programming protocols that may be specific to one instrument. Typically, instrument drivers expose an API that is used within a programming environment to build application software. Selecting the correct instrument driver is crucial for those developing a hybrid test system, especially when implementing a custom hardware abstraction layer (HAL) within the test system.
LabVIEW integrates directly with Plug and Play instrument drivers to ensure long-term scalability of hybrid test systems. These drivers allow for customization to the source code in order to accommodate specific test requirements and scale with evolve over time. LabVIEW Plug and Play instrument drivers are based on VISA and provide an additional layer of abstraction from the hardware to address the long-term concerns of hardware interoperability – you never have to worry about communication details across a given bus. LabVIEW Plug and Play instrument drivers ensure the life of your test system regardless of the bus, platform, or OS.
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