Address Modern Data-Logging Challenges Using CompactRIO With NI-DAQmx

As technology advances, test engineers face the challenge of testing increasingly complicated designs with shrinking budgets and timelines. More intricate products demand more flexible test solutions, which means data loggers must be modifiable and scalable to meet new challenges without raising costs.

CompactRIO with NI-DAQmx provides intuitive and accurate data-logging capabilities to help you tackle modern test requirements. You can stay ahead of these ever-changing requirements using headless operation, added reliability/uptime, and the future-proofing provided by a user-configurable FPGA. With the release of the value cRIO-905x CompactRIO Controllers, this versatile solution is more affordable than ever before.
 

Figure 1. The new value CompactRIO with NI-DAQmx.

Modern data logging is complex, and tests require combinations of electrical and mechanical measurements and communication protocols. Test engineers need accurate data-logging equipment and quick, intuitive software to reduce development time and get products to market faster.

To extract useful insights from a test, the data you acquire must be as accurate and noise-free as possible. NI ensures that the quality of your measurements is never compromised with its C Series I/O modules, which feature built-in signal conditioning, filtering, and high-accuracy analog-to-digital converters. One CompactRIO Controller can hold up to eight hot-swappable C Series modules that provide different measurement functionality. NI offers over 150 C Series modules to ensure you can connect to any sensor on any bus.

Figure 2. Choose from over 150 C Series I/O modules for a truly customizable data logger.

CompactRIO works with NI-DAQmx, National Instruments’ data-logging driver that offers a standardized programming interface to help you increase productivity and performance. You can use the consistent API of NI-DAQmx for analog I/O, digital I/O, and counter measurements across multiple hardware platforms and programming languages. This helps you apply your skills to many testing situations and hardware variations.

Figure 3. Take measurements quickly and intuitively with DAQmx on CompactRIO.

The precision and accuracy of these C Series I/O modules, combined with the flexible NI-DAQmx driver, form an effective solution that can adapt to changing test requirements.

Clinical lab results no longer address the challenges presented by modern tests and regulations, so engineers are increasingly using physical system tests in rugged, real-world environments. Devices under test (DUTs) may be in locations unfit for a desktop PC, like a noisy factory floor. Or you may need a mobile measurement system that you can place onboard your DUT, like in automotive in-vehicle data logging. These applications require a compact, rugged, and portable solution for embedded data acquisition.

Headless operation means that your CompactRIO device is a stand-alone computer in a rugged, compact shell. This provides freedom from a development P. You can take your CompactRIO device directly to the point of test and leave it there. Placing your embedded data acquisition system closer to your DUT means that your wires pick up less noise, which increases your system’s accuracy. You can also easily replicate and scale your data acquisition system. If you need to log data from multiple assets, you can deploy the same code to multiple headless CompactRIO targets.

Figure 4. Headless operation gets you closer to your sensors.

CompactRIO provides an operating temperature range of -40 °C to 70 °C in addition to 50 g shock and 5 g vibration ratings. It also offers international safety, Hazloc, and environmental certifications for operation in harsh industrial environments. You can take advantage of this ruggedness to create an independent, robust data-logging system like NASA did.

Running long-term tests introduces the challenge of maintaining accurate, synchronized data over a timeline of days, weeks, or even months. Data corruption or a crash could quickly erase valuable data and push back project completion timelines. The more reliable your data-logging system, the more confidence you can have that you’ll get the data you need on time.

A real-time operating system (RTOS) executes tasks with precise timing requirements. An application running on a RTOS is said to be deterministic if the timing is guaranteed within a certain margin of error. A traditional OS such as Microsoft Windows 10 prioritizes system tasks like mouse movement, but RTOSs elevate the priority of the tasks you define as mission-critical above all others.

Figure 5. Comparison of prioritization in real-time vs general-purpose operating systems.

What does real-time reliability mean for your data-logging application? In applications for which downtime is costly, a RTOS can prioritize “watchdog” routines that check for faults, log data, and restart the system to help you avoid crashes and minimize lost data. Systems with a RTOS are also great fits for control applications; you can be sure that critical communication (stopping rotating equipment, sending restart commands to other controllers in a system) is sent on time to avoid failure.

Data-logging engineers are consistently under pressure to test more and to test differently. The projects often start small. A need to measure a few channels of data off a device at a desk. However, if the solution’s hardware has limited functionality, engineers may not be able to modify it for the next test need or unforeseen challenge like adding a new measurement type, implementing synchronization, or raising measurement fidelity.

Figure 6. CompactRIO can use complex I/O like vision, motion and communication components.

Consider a program like Microsoft Excel. A spreadsheet analyst can get started with it quickly and still use its many advanced features for more complicated situations. Similarly, for an engineer with data-logging needs, CompactRIO with NI-DAQmx provides an intuitive, out-of-the-box data-logging experience. It also includes functionality that isn’t required to get started but can help you meet future test requirements.

Each CompactRIO device has an onboard FPGA, which is a powerful silicon chip that physically rewires itself to provide faster I/O response times and specialized functionality. This means you can support loop and measurement rates up to 10s of megahertz, process and analyze data, and offload other time-critical tasks without added hardware. The onboard FPGA also makes available more complex I/O including vision, motion, or industrial communication protocols. These features ensure your data-logging system is future-proof to meet the timelines of today and the challenges of tomorrow.

When tackling a new data-logging need, a fast solution is critical. However, this timely solution shouldn’t prevent you from being prepared for the next, more complex challenge. CompactRIO provides both the speed of setup and depth of features necessary to meet a wide range of test requirements.

The inclusion of the NI-DAQmx driver with CompactRIO gives you an intuitive programming interface for your data-logging needs. An RTOS allows for long-duration testing, and the ability to run headlessly gets your CompactRIO device closer to your test to provide more accurate data and require less manual oversight. A programmable FPGA on your chassis future-proofs your system by giving you the option to include more complex I/O, more demanding processing, and loop rates up to 10s of megahertz for fine-tuned control.

Just as Excel presents a solution for spreadsheet needs from simple to complex, the features of CompactRIO with NI-DAQmx deliver an expedited time to the first measurement while meeting more difficult and complex data-logging challenges.

• Learn more about the CompactRIO Controller
• CompactRIO Systems Product Page
• Getting Started with NI CompactRIO
• Learn how FlexLogger can make data logging easier
• Read about NI solutions for electromechanical component validation data logging