Need LabVIEW Real-Time programming help? | LabVIEW Real-Time Developers 2019-02-14T07:59:29+00:00

LabVIEW Real-Time Programmers

  • Over 1,000 LabVIEW RT based solutions delivered

  • Platinum-level National Instruments Alliance Partner, putting us in the top 2% worldwide

With over 1,000 LabVIEW Real-Time based solutions under our belt, we’ve utilized RT for a number of test and industrial embedded applications.  It’s great for applications requiring deterministic timing.

Dr. James Campbell
Dr. James CampbellPresident

The combination of LabVIEW RT and the RTOS on which it runs allows for the creation of applications with bounded jitter and latency.

Viewpoint uses LabVIEW RT (and LabVIEW FPGA) for applications that require reliable and timely code execution.  These applications generally have particular characteristic needs:

  • Operator safety from fault conditions
  • Equipment protection from fault conditions
  • Reliable control algorithms
  • Fair to good synchronization of signal I/O without HW clocking

We’ve used LabVIEW RT to develop many real-time solutions, falling into these application areas:

  • Product validation
  • Endurance testing
  • Machine monitoring
  • Production/manufacturing testing.
Want us to develop a LabVIEW RT solution for you?

Want more proof points?  Check out these Real-Time case studies:

Online Monitoring of Industrial Equipment using NI CompactRIO

monitoring and control for electrical power generation

Online Monitoring of Industrial Equipment using NI CompactRIO

Improving Maintenance of expensive industrial equipment

Client – Large Industrial Equipment Manufacturer


The maintenance of the equipment was not always done at the prescribed intervals because the cost of shutting down the plant is significant. This sometimes resulted in an equipment failure. This particular application is for equipment/machinery in the energy/power industry (a generator).


The online monitoring system monitors a particular parameter of interest to send warnings and alarms to the control room so that the operators know when maintenance needs to be performed on the particular part of interest.  This system has been installed in multiple plants.


  • Enables condition-influenced maintenance intervals vs periodic intervals
  • Reduces probability of catastrophic failure by providing warning indicator

System Overview

The system monitors the generator collector health. NI-based data acquisition hardware acquires the signal of interest, logs the raw data, processes the parameter of interest, and triggers/sends warnings and alarms to the control room.  LabVIEW FPGA was used for analog and digital IO and a sensor check. LabVIEW Real Time was used for the calculation, data logging, serving data to the HMI and alarm/warning checking.

Touchscreen GUI for data/alarm display and system configuration
Data logging
Signal processing and alarming
HARDWARE USED (selected by customer)
NI Touch Panel Computer
Multiple NI C Series Modules

*- images are representative, not actual

I want an online monitoring solution »

Endurance Testing using NI PXI

Endurance Testing using NI PXI

An automated system permits faster validation, unattended test, an increase in throughput, and can free up resources for other tasks during the weeks long endurance test.

Client – A manufacturer of aircraft components in the mil-aero industry


New product development drove the need for a new endurance test system for product validation. The old systems were not designed to test the newly designed part (aircraft actuators), and the company didn’t have the time or resources to reconfigure existing systems to perform the testing required.


The new PXI-based endurance test system provides automated electromechanical testing, full data recording, report generation and a diagnostic panel for intelligent debug. Viewpoint selected the NI equipment, while the test consoles, and other components were selected and fabricated by the customer.


  • An automated system permits faster validation, unattended test, an increase in throughput, and can free up resources for other tasks during the weeks long endurance test.
  • Full data recording with a data viewer enables post analysis, which provides the ability to review and analyze raw signals captured during execution. Channel examples are actuator LVDT position, load, current, and encoder actuator position.
  • Summary report capability allows the customer to document the amount of testing completed against the full endurance test schedules.
  • A manual diagnostic operational panel provides the ability to verify particular DUT functionality or components without running an entire schedule.
  • Systems can be paused and restarted to allow for “scheduled maintenance” of the DUT such as inspections, lubrication, etc.

System Overview

The PXI-based endurance test system enables data collection, deterministic PID Loop Control, emergency shutdown and a diagnostic panel for manual test and debug operation. The system runs endurance test schedules, that are defined as a recipe for test execution. These schedules, which are customer-defined and DUT-specific, are designed to simulate the actual conditions the DUT would see in real world application as closely as possible. LabVIEW-RT was used for the deterministic looping for Closed Loop Control of Actuator Position and Load Control. LVDT demodulation was performed on a PXI FPGA card programmed with LabVIEW FPGA.

Summary Reports
Full Data Collection for Real-Time and Post Analysis
Deterministic PID Loop Control
E-Stop Management
Diagnostics Panel for Manual Test and Debug
Endurance Test Schedule Execution
Hydraulic Control Panel for Source & Load PSI Control
Various PXI-based Data Acquisition Cards
PXI RT Controller

Endurance Tester for Mission-Critical Mechanical Component using NI cRIO

Endurance Tester for Mission-Critical Mechanical Component using NI cRIO

Ability to run tests unattended and overnight reduces operator labor and compresses test schedules

Client – Major Aerospace Component Supplier / Manufacturer


The client had an older VB & PLC-based test system in place already, but it was obsolete. A new endurance test system needed to be developed to validate prototyped components (in this case, aircraft & aerospace bearings). Many of the prototypes are one-off, so it was important that the test system not destroy the component.


A new endurance test system was developed to validate prototyped components. The test system can be configured for automatic shutdowns so as not to destroy the component under test in the event of unexpected performance of electro-mechanical subsystem components. The updated endurance tester supports product validation by allowing the product to run under various test conditions (e.g. speed, load, oil flow, temperature) and collecting data for analysis.

Viewpoint developed the software and selected the NI hardware (other hardware was selected by the client).


  • Ability to run tests unattended and overnight eases operator labor and compresses test schedules

  • Data collection allows for offline engineering analysis

  • Automatic shutdowns reduce destruction of the prototype component under test

System Overview

The updated cRIO-based endurance tester incorporates configurable profiles, data logging, and automatic shutdown to allow for safer extended validation testing.  LabVIEW FPGA and LabVIEW RT were used together to interface with the test hardware sensors and controls.  LabVIEW as used create the HMI for the test system.

Closed loop control of bearing test oil flow
Axial load control
Driver for Emerson VFD
E-Stop and safety management (shutdowns based on alarm limits)
Data collection – temperature, pressure, flow, vibration, frequency
Operator/Diagnostic GUI for control of system
NI CompactRIO (cRIO)
NI C Series Current Input Module
NI C Series Voltage Input Module
NI C Series Temperature Input Module
NI C Series Current Output Module
NI C Series Analog Input Module
NI C Series Sound and Vibration Input Module
NI C Series Digital Module
Emerson VFD (Variable Frequency Drive)
TCP Modbus

Product Validation using LabVIEW RT & LabVIEW FPGA – Electromechanical Actuator Test Stand

Product Validation using LabVIEW RT & LabVIEW FPGA – An electromechanical actuator test stand

Automated testing reduces operator man hours and increases production throughput.

Client – A manufacturer of actuators in the mil-aero industry.


New Product Introduction (in this case a new controller and new actuators) drove the need for a new automated electromechanical test stand.


New NI PXI-based electromechanical test equipment provided automated testing, report generation, and SPC data generation.  The sequencing of the test procedure, reporting, and verifiable results were managed with the StepWise platform.


  • Automated testing reduces operator man hours and increases production throughput.
  • Meets strict customer requirements regarding testing and data recording in a verifiable manner.
  • Automated Test Report Generation.
  • Collects data to support SPC (Statistical Process Control).
  • Ability to obtain the internal state of the controller FPGA via the LVDS communication link.

System Overview

Viewpoint developed the software and selected NI data acquisition and control hardware for the test stand.  There are several layers of software functionality.

Test sequencer
Test steps (e.g. Frequency Response, Step Response, Dynamic Stiffness, Fault Response, Power Consumption)
Test Report Generator
Data acquisition
1553 comms
Function generator
Error detection
Synch data from 3 sources (tester, UUT, external DAQ device)
Stream high-speed data to disk
Stream high-speed data to analog outputs for engineering use
Custom communication protocol used by UUT over LVDS lines
NI FlexRIO card with LVDS adapter module
Multiple NI R Series cards
High speed, high voltage, isolated analog input cards
MIL-STD 1553 bus
Custom TCP/IP

*- images are conceptual only, not actual

Yes, I need an automated test system »

Industrial Embedded Control for Advanced Manufacturing

Industrial Embedded Control for Advanced Manufacturing

Energy & Aerospace components manufacturing

Client – Automated Dynamics


Utilize laser energy to heat thermoplastic or thermoset composite during an automated fiber placement manufacturing process.


Starting from a proof of concept developed by Automated Dynamics, Viewpoint developed the industrial embedded laser controller software for the automated fiber placement manufacturing equipment. The hardware utilized was an off-the-shelf CompactRIO controller from National Instruments.


  • High-speed temperature control

System Overview

See it in action here:

I need an embedded control solution »

Industrial Embedded Monitoring & Control of Manufacturing Equipment

Industrial Embedded Monitoring & Control of Manufacturing Equipment

Adding Closed-loop Precision Control to Manufacturing Process with multiple international plant deployments

Client – Quantum Engineered Products Inc.


Quantum produces manufacturing machine components that are used in the glass bottle forming process.  Specifically, they supply plunger mechanisms that are used in the initial blank side formation of the glass bottle.

The engineers at Quantum recognized that they had an opportunity to improve the bottle formation process by adding position sensing to their plunger mechanisms. The ability to sense and record plunger positions would enable machine operators to monitor the travel of the Quantum plunger into the molten glass gob within the blank side mold, identify and diagnose potential hardware problems, and provide real-time feedback that could be used to better control the process.

Quantum needed a partner to implement real-time control and monitoring of the bottle forming process and selected Viewpoint for the task.


Viewpoint developed custom monitoring and control software that runs on off-the-shelf hardware.  The software developed for Quantum is called TFA™ (Total Forming Analysis).  The TFA™ software is a process monitor and control system for the hot side of the bottle forming process.

The software takes position information from the plungers Quantum supplies to the factories to show the travel of the tube during the forming process. The software measures key aspects of the plunger position profile such as initial plunger load position, final position, and dwell time at the final position.  When these measurements are found to be out of tolerance, the software communicates with the machine auto-reject system to ensure that bad bottles are removed from the system.

Moreover, the final plunger position is used as feedback to do closed loop control of the glass gob weight, controlling glass feeder tube height and/or needle heights to change the glass gob weight. This allows for precise control of container weight, making the most efficient use of raw materials while ensuring container quality.

To accommodate multiple end-customer-driven hardware configurations, the off-the-shelf hardware selected was based on the National Instruments CompactRIO family of chassis to enable configuration of various input/output signal requirements.

For the end result, check out one of the machines running TFA™ in action:



Hardware Customization Flexibility –  every one of Quantum’s customers wants something either a little or a lot different with their particular instance of the system.  Using modular hardware allowed for swapping of I/O hardware.

Quick Response to Software Feature Requests – Quantum and Viewpoint were in constant communication to be able to implement new features and tweaks on fairly short notice (generally within a couple of weeks).

On-Site Support – Viewpoint engineers travel to Quantum’s customer sites with them as a team upon request.

System Overview

The embedded process monitoring and control system consists of custom process monitoring and control software that runs on off-the-shelf hardware.

NI 9148 Ethernet expansion chassis
NI 9201 module for AI
NI 9425 module for DI
NI 9476 module for DO
Data Acquisition and Processing
Waveform Calculations (eg. final position and dwell time)
Final Position control loop
Real-time per cavity plunger position graphs
Process trend graphs
Forming history graphs, showing a packet of the last forty final positions per cavity
Limits definition screens
System health summary, fault monitoring and auto-reject configuration
Job configuration
Plunger sensor calibration
Gb Ethernet communication with the DAQ devices (NI 9148 chassis)
TCP/IP Modbus communication with Schneider Electric motors for feeder tube and/or needle control

TFA™ is a registered trademark of Quantum Engineered Products, Inc.

I need an embedded monitoring/control solution for my equipment »

Industrial Embedded – Using a cRIO for Rapid proof-of-concept Prototyping | FPGA-based motor control & RT-based loop control

Industrial Embedded – Using a cRIO for Rapid proof-of-concept Prototyping

FPGA-based motor control & RT-based loop control.

The NI cRIO platform allowed for rapid development/test cycles. There was as little as ~1.5 hours between a software change and a test.


This was a rapid proof-of-concept prototyping effort to quickly determine feasibility of auto-pilot flight.


The cRIO-based controller was able to allow the helicopter to auto-pilot routed waypoints.


The NI cRIO platform allowed for rapid development/test cycles.  There was as little as ~an hour and a half time between a software change and flight test.  Code updates could be flight tested in the morning, updated over lunch, tested again in the afternoon, updated one more time at night, and flown again the next morning.  This allowed for rapid development of control laws.

System Overview

The core system functionality consists of:

  • resolver-based BLDC motor control
  • position loop control
  • vehicle dynamics control
  • and flight logging.

Vehicle dynamics control and position control lived on the RT processor, while motor control and critical high-speed processing lived on the FPGA.


Designing an Automated Fuel Cell Validation Test Stand

Designing an Automated Fuel Cell Validation Test Stand

Verifying a New Fuel Cell Design Through Automated Operation

Client: A major automotive manufacturer

Problem Scope

Micro Instrument, an automation vendor that builds test and validation stands, has extensive experience with programmable logic controllers (PLCs) and stand-alone controllers for controlling repetitive motion, safeties, and other “environmental” parameters such as pressure and temperature. The company typically uses PLCs to reliably deliver discrete I/O control and standard PID loop control.

However, Micro Instrument’s customer, a major automotive company, was interested in investigating fuel cells as a power source and they needed to run these fuel cells under a wide range of conditions for extended durations, for both design validation testing and durability testing purposes. Furthermore, the client wanted to implement more advanced control algorithms than simple PID.


The customer knew they needed control loops that predicted system response so we could eliminate overshoot and/or achieve a faster approach to a setpoint. But, because the customer did not know in advance exactly what such “smart” controls would entail, it was beneficial to have the full power of LabVIEW to develop such controls. Providing this functionality with a PLC would be cumbersome, if not impossible.

The customer had some Compact FieldPoint which they wanted to use for this project, so we needed to ensure that this equipment would be sufficient to deliver the required control performance and tolerances. Also, the system needed to conduct PID control in two forms – PWM and continuous control. Importantly, this Fieldpoint hardware had a real-time controller running LabVIEW Real-Time.


We developed a flexible control environment using NI Compact FieldPoint and LabVIEW Real-Time to meet the customer’s system control demands. For example, to predict system response, we programmed the Compact FieldPoint to run control loops that were aware of imminent system-state changes and changed their control schemes accordingly.

As with most validation test systems, we needed to monitor conditions for safety. New product designs are often operated near the edges of safe operation in order for the designer to understand how the product performs in extreme conditions. For this fuel cell application, destructive over-heating and over-pressure could occur. Both digital and analog signals were watched in real-time to assure operation within reasonable bounds and allow a safe shutdown if the fuel cell ran into out-of-bound conditions.

The application used the following independent parallel loops:

  • Seven for PWM-based temperatures control
  • Two for continuous pressure monitoring
  • Four for solenoid and sensor monitoring and control
  • 15 safety loops

Data collected during the validation tests were saved to a local PC for later performance analysis and anomaly detection.

The combination of Compact FieldPoint with LabVIEW Real-Time enabled the customer to run the required custom control algorithms and it surpassed the capabilities offered by standard PLCs.

Production Test of Large Uninterruptible Power Supplies

Production Test of Large Uninterruptible Power Supplies

Manufacturing Test of UPS Units Designed for Data Center Backup Power

Client: A major manufacturer of data-critical three-phase uninterruptable power supplies


A major manufacturer of very large three-phase uninterruptible power supplies (UPSs) needed better measurement, analysis, and report generation capabilities. Their clients used these UPSs on mission critical equipment, such as data warehouse server farms, communications equipment, and so one. Existing testing procedures used equipment that did not allow for complete simultaneous coverage of all sections of a UPS unit, from input to output. Our client wanted a better understanding of the signals on each of the three phases at various locations within the UPS, especially when power sources were switched or faults were induced.

Also, in the prior test procedure, factory acceptance reports were manually assembled for our client’s end-customers, delaying the final sign-off. Finally, since the end-customer might want to run a specially configured test or run a series of tests in a different sequence than some other end-customer, our client wanted to be able to rerun certain types of tests or run tests in a customer-specific order. Thus, the test sequencing needed to be flexible and editable, possibly on the fly.

Finally, synchronization between the data collection on all signals was critical to assess functionality, since all 3-phases of the UPS output needed to be in the proper timing relationship.


At a high-level, the majority of testing a UPS relies on knowing the reaction of the UPS to changes on the input side (such as a grid power outage) and changes on the output side (such as an immediate heavy load). Thus, many of the tests performed on a UPS deal with power quality measurements, such as defined by IEEE 519 or IEC 61000 series standards, which cover both continuous and transient operation.  The StepWise  test execution platform was utilized to allow the customer to develop arbitrary test sequences using the application specific test steps developed for the program.

Our solution used a cRIO to measure both current and voltage from each leg of the 3-phase power (and neutral) by using appropriate cSeries modules connected to various voltage and current test points within the UPS. The cRIO had enough slots to allow a single cRIO to measure a single UPS.

Assessment of continuous operation mainly reviewed the UPS output power quality. Here, it was important to know the amplitude and phase of each leg of the 3-phase power. Synchronous data acquisition between all voltages and current channels was needed for proper timing alignment of collected data points.

Assessment of transient operation was often a review of power ripple and recovery time. For example, in the event of grid power loss, a UPS would switch over to backup power, with the result being a small transient created on the output a UPS. Again, the voltages and currents needed to be collected synchronously to assure that event timing was aligned.

For increased power capacity, the UPSs could be connected in parallel. When ganged together, the continuous and transient behavior of each UPS needed to be compared to the others, in order to capture the behavior of the entire combined system. Consequently, each cRIO (one per UPS) had to share a clock to enable synchronous data collection across all cRIOs. A timing and synchronization module was placed into each cRIO chassis with one cRIO acting as the master clock source and the others being slaved to that clock.

The overall test system architecture has a master PC communicating with each cRIO. Each cRIO was placed in certain activity states by the master PC, such as “arm for measurement”, “transfer collected data”, and “respond with system health”. This arrangement enables the number of cRIO to shrink or grow depending on the number of UPSs being testing in parallel.


The test system connected the timing module in each cRIO in a daisy-chained configuration, leading to data sampling synchronization error of less than 100 ns between all cRIOs, which translates to about +/-0.001 degree phase error for 60 Hz power signals. This timing synchronization was more than sufficient to analyze the collected waveform data for power quality and transient structure.

LabVIEW was used to create various configurable test steps that could be executed in random order as well as in an automated sequential manner. Our client was thus able to test a UPS in a predefined manner as well as react rapidly to queries from their customer when they were viewing a factory run-off test. For example, the customer might ask to re-run the same test several times in a row to validate consistent responses.

Each type of test included automated analysis routines that numerically calculated the relevant parameters against which the UPS was being checked. Not only was this automated calculation faster, but it reduced mistakes and improved reproducibility as compared to the previous post-testing partially manual calculations.

Data from all tests, even repeated ones, on a given UPS were archived for quality control purposes and made a part of the device history for that UPS.

Finally, the report generation capability built into this test system was far superior to the previous methodology by allowing our client to hand their customer a professional report package practically immediately the testing was complete. Customer satisfaction was improved substantially with this state-of-the-art test system.

Manufacturing Test – for mission-critical components

Manufacturing Test – for mission-critical components


Using PXI & LabVIEW RT

Client: A major manufacturer of implantable cardiac and neural stimulators


Our client needed several extremely reliable test systems to test the batteries that power their implantable medical devices. These new test systems were needed for two main reasons. First, the needed to upgrade existing obsolete test equipment, based on antiquated hardware and software. Second, new battery designs could not be tested on the old equipment.

A critical aspect of the new test system was the need to detect any excessive charge being extracted from the battery, thus rendering it unsuitable for surgical implantation. Thus, the test system needed to monitor the total energy withdrawn from a battery during testing to assure that it never exceeded a certain limit while also offering precise control of the type of pulses being drained from a battery.

All test results had to be stored in a database in order to maintain device history for each battery manufactured for archiving, quality control, and process improvements.



The updated manufacturing test system is PXI-based along with a custom micro-controller-based circuit board for some low-level control. Each PXI controller communicated to the microcontroller (uC) on the custom PCB via CAN. The uC controlled the current drain from the battery while monitoring actual current and voltage from the battery at over 1000 samples per second using a precision 6.5 digit PXI DMM. Additionally, each PXI chassis was used to test many hundreds of batteries. Signal connections were handled by several switch multiplexers. Overall control of all the PXI testers was managed by a host PC connected to the PXI controller.


  • Reduced test system cost vs complete COTS solution with combo LabVIEW RT on PXI and firmware on microcontroller-based custom circuit board
  • Enabled tight control of DUT operation on controller with microsecond level responsiveness while being supervised by higher-level PXI RT
  • Quick-reaction test abort capability
  • Test results stored to database for archiving, quality control, and process improvements

System Overview

In a simplified view, the testing proceeded by pulsing the battery with a series of different durations and varying amperages. The exact sequence of this pulsing is unique for each DUT model. Measurements were made using a PXI filled with various NI boards such as DMMs, for accuracy, and data acquisition cards, for general purpose use.

Additionally, the pulsing amperage levels needed to be tightly controlled in order to know that the tests have been performed properly. Thus, a real-time amperage control scheme had to be implemented to maintain the level requested for the pulse. We chose to accomplish this control via an analog control circuit developed using a custom Viewpoint-developed circuit board. This board was controlled via a Microchip PIC microprocessor. The LabVIEW RT application communicated with the microcontroller to setup the pulsing sequence and coordinate the start and stop of the pulsing and the NI acquisition hardware.

This custom circuitry also reduced the overall cost of the test system by about 40%.

The engineering time to design this custom circuitry was more than offset by the reduction in material costs because more than 10 test systems were deployed, allowing the non-recurring engineering effort to be shared between many systems.

When no critical issues were detected, the waveforms acquired by the PXI system were stored and then analyzed to determine the viability of the DUT. The pass/fail disposition, the waveforms, the total energy consumed, and other test results were then passed along to a master PC that managed all these results in a database for archiving, quality control, and process improvements, each set of results being tied to the unique unit serial number.
The test systems provided reliable operation for testing the large annual production volumes of the mission-critical DUTs.

LabVIEW RT – for managing the microcontroller functions and overall data collection and safety monitoring
Microcontroller application – to provide precision pulsing of the batteries
Communicate to the host PC – to both receive pulsing instructions and configurations and to return pulse waveforms for each battery tested.
PXI chassis & controller
PXI analog input modules
SCXI multiplexing switches
Ethernet TCP-IP

High-Speed Digital Record and Playback Solution


High-Speed Digital Record and Playback Solution


At maximum throughput, the systems needed to consume during record and produce during playback about 800 MB/s/slot.


Client: A large company involved in C4ISR


A large company involved in C4ISR was developing a system for a new high-speed digital sensor device. Viewpoint was contracted to build a test system used in design validation and ultimately endurance testing of the sensor. Since the sensor was a component of a larger system which was being developed at the same time, another test system was created to simulate the sensor by feeding signals into the system.


Both the amount of data and the frequencies of the various digital signals were nearly at the limit of hardware capabilities. At maximum throughput, the systems needed to consume during record and produce during playback about 800 MB/s/slot. The FPGA clock on the FlexRIO had to run up to 300 MHz. The skew between triggers for data transmission needed to be less than 5 ns even between multiple FlexRIO cards even when the parallel data paths has inherent skews associated with the sensor. Finally, the systems needed to handle clocks that might be out-of-phase.

Achieving these requirements required significant engineering design in the face of multiple possible roadblocks, any one of which could have eliminated a successful outcome.

Furthermore, as usual, the development timeline was tight. In this case, it was a very tight 3 months.

Viewpoint’s Solution

To meet the timeline, we had to work in parallel across several fronts:

  • LabVIEW-based application development for both record and playback
  • LabVIEW FPGA development for marshalling data between the controller and DRAM
  • Custom FAM circuit board design and build
  • FlexRIO FPGA CLIP nodes and code for low-level data handling

Technical Highlights

This sensor had several parallel data paths of clock and data lines with clock speeds up to 300 MHz on each path requiring exacting design and build of a custom FlexRIO Adapter Module (FAM) and unique custom CLIP nodes for extending the FlexRIO FPGA capabilities. The FAM also had a special connector for interfacing to the customer’s hardware.

Additional NI hardware and software completed the system components.

LabVIEW Layers

The host application, written in LabVIEW, managed the configuration of the data acquisition and the control of the LabVIEW RT-based FlexRIO systems. The configuration primarily dealt with the number of sensor channels in use, skew settings between digital lines, and other parameters that dealt with the organization of the data passed between the sensor and the FlexRIO.

Two FlexRIO applications were written, one for record and one for playback. Each FlexRIO application was written in LabVIEW, and managed the configuration of the FlexRIO cards and the movement of data between the FlexRIO cards and the RAID drives. Note that Windows supported for the RAID driver. Between 10 and 32 DMA channels were used for streaming, depending on the number of sensor channels being used.

And, each FlexRIO application had an FPGA layer, written in LabVIEW FPGA enhanced with custom CLIP nodes. For the record application, we developed a custom DRAM FIFO on the FPGA to assist with the latencies on the PXIe bus. For the playback application, we were able to stream directly from DRAM.

FlexRIO Considerations

The FlexRIO and stock FAMs from NI were initially considered as candidates for this project. Clearly, working with commercial-off-the-shelf (COTS) components would be most effective. Three options were available at the project start which could accommodate the required clock frequencies, but none offered both the required channel counts and skew/routing limitations. Hence, we had to design a custom FAM. This decision, made before the start of the project, turned out to be wise in hindsight because the parallel development path resulted in some shifts of sensor requirements which could be accommodated with the custom FAM but might have led to a dead-end with a COTS FAM.


In LabVIEW FPGA, a CLIP Node is a method to import custom FPGA IP (i.e., code) into a LabVIEW FPGA application. CLIP stands for Component-Level Intellectual Property. We needed to use special Socketed CLIP Nodes (i.e., VHDL that can access FPGA pins) for this project because we could expose additional features of the Xilinx Virtex-5 not exposed in LabVIEW FPGA by accessing Xilinx primitives. Some specific features were:

  • Faster FPGA clocking
  • Additional clocking options
  • Individual clock and skew control
  • Custom PLL de-jitter nodes

Essentially, the FPGA design had a majority of FPGA code developed in LabVIEW FPGA and we used CLIP Nodes for interfacing the signals between the FlexRIO and the FAM.


FlexRIO Adapter Module

As mentioned earlier, we had to create a custom FAM because of the need to route high speed signals from customer-specific high density connectors while synchronizing signals across multiple data channels and FPGA modules to within one (300 MHz) clock cycle.

At these high-speeds, the FAM needed careful buffering and impedance matching both on the signals as well internal components on the FAM PCB. At the start of the design, we utilized Mentor Graphics HyperLynx High Speed DDR signaling Simulation software to minimize signal reflections prior to building actual hardware. This step saved countless hours in spinning physical hardware designs.

We designed the FAM to allow channel routing and access to additional clock and trigger pins on the Xilinx chip and PXIe backplane.


The choice to base these digital record and playback systems on NI hardware and software was critical to completing this project. The open architecture in both hardware (custom FAM) and software (CLIP Nodes) enabled us to include some very creative extensions to the base toolset without which the project would not have succeeded in the allotted pressured schedule and on a predetermined budget. We were able to stretch the capabilities of the hardware and software very close to their maximum specifications by combining COTS and custom much more cost effectively than a purely custom design.

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Condition Monitoring – Improving the Uptime of Industrial Equipment

Condition Monitoring – Improving the Uptime of Industrial Equipment

Monitoring the Health of Industrial Equipment

Client: A large industrial company that uses industrial-grade compressors.


  • Increase awareness of potentially harmful operating conditions.
  • Record detailed data upon event detection.
  • Reduce unnecessary equipment shutdowns due to spurious vibration transients.


We utilized an off-the-shelf controller (NI cRIO) combined with custom software in order to augment and create the first system with ~2 man-months of effort. This solution has been installed in several facilities and is projected to be installed in hundreds of facilities around the world.


  • Send alerts via email when potentially harmful operating conditions occur.
  • Record detailed data upon event detection for failure analysis and predictive maintenance.
  • Suppress spurious vibration transient signals to reduce unnecessary equipment shutdowns.

System Overview


Condition Monitoring for Electric Power Generation

Condition Monitoring for Electric Power Generation

Monitoring generator and turbine components of power generation equipment

The CompactRIO-based system has allowed for continuous monitoring, rather than just a periodic review of turbine and generator performance. In addition, by combining the FPGA and the RT processor in a physically small device, the solution has been able to ensure very fast data acquisition, data reduction, and sophisticated analysis.

Client: A multi-national power generation equipment manufacturer


Continuous monitoring of power generation equipment can have a great impact on maintaining a reliable flow of power to consumers as well as alerting the power generation equipment operator to potential equipment damage if timely repairs are not made.

This case study will focus on two measurement systems utilized by a multi-national power generation equipment manufacturer to monitor the generator and turbine components of their power generation equipment.

The manufacturer’s systems needed relatively high-speed waveform sampling, well-suited to the National Instruments CompactRIO platform. Viewpoint Systems provided technical assistance in the development of these systems.


The difference in the types of analyses and data rates of the measurement systems required a flexible yet capable hardware platform. Each system needed to work on a generator outputting 50 Hz AC or 60 Hz AC.

Viewpoint’s Solution

The CompactRIO  platform and LabVIEW proved to be an excellent solution for the electric power generation condition monitoring system’s data acquisition and analysis needs. The small size and robustness of CompactRIO allowed the system to be placed at a preferred location. In both the flux probe and the blade tip timing, the CompactRIO FPGA could acquire and pre-process the data. The CompactRIO successfully managed – and continues to manage – all analysis, data archiving, and communication with a host PC.

In the case of the tip timing, the data rates were high enough that the detection of the tip location for each signal needed to be performed in the FPGA so that the real-time (RT) layer received a much-reduced data rate of tip locations. The RT processor was able to perform higher level analyses on these timings. Occasionally, a snapshot of a raw tip timing waveform could be passed to the RT processor for archiving and presentation to an engineer. However, due to the data bandwidth and processor loading of the CompactRIO, such snapshots must be infrequent.

For both systems, a master PC managed the operator user interface, long-term data collating, reporting, and archiving of files and statistics. Each CompactRIO connected to this master PC via a TCP/IP connection.


The CompactRIO-based system has allowed for continuous monitoring, rather than just a periodic review of turbine and generator performance. In addition, by combining the FPGA and the RT processor in a physically small device, the solution has been able to ensure very fast data acquisition, data reduction, and sophisticated analysis. By deploying CompactRIO devices, the multi-national power generation equipment manufacturer achieved a cost-effective method of monitoring the power generation facility equipment, ensuring detection of operational issues quickly and easily.

Technical Highlights

Both measurement systems described required sampling rates greater than 10 kHz, restricting the use of traditional PLC-based data acquisition devices and requiring a programmable automation controller (PAC). Each system measured the performance by connecting to special sensors and associated signal conditioning, provided by our customer, such that the data acquisition equipment only needed to support ±10 V signals. Furthermore, each of these systems needed to push data to a master PC for data trending, result archiving, and operator display.

Despite the significant differences in the measurement types, Viewpoint Systems was able to utilize a common set of data acquisition, processing, and connectivity tools, based on the NI CompactRIO platform and LabVIEW, to monitor the system.

More information about each measurement system follows.

Flux Probe

The flux probe system looks for shorts in the windings of the generator. Each time a winding passes under the flux probe, the probe output increases. When a winding is shorted, the field created by the winding is reduced and detected as a lower amplitude output by the flux probe. The position of a shorted winding inside the generator can be located by measuring a key-phasor signal that pulses once per revolution and converting the timing offset of this weakened signal into an angular position. Both flux and key-phasor signals are measured at about 50 kS/s.

Figure 1 shows an example signal output by a flux probe. The local peaks are indicative of winding current. Automated analysis of the amplitudes of the flux signals can be challenging due to changing waveform shape as a function of generator load and severity of shorts.


Figure 1 – Example flux signal over a single rotation

A good reference of the flux probe technique is described in the Iris Power Engineering article, “Continuous Automated Flux Monitoring for Turbine Generator Rotor Condition Assessment.”

Turbine Tip Timing

The turbine tip timing system looks for displacement of each turbine blade tip from nominal position. At slow rotational speeds, the spacing between each tip closely follows the uniform blade spacing. At higher speeds, vibrations and resonances can make the blade tips wobble slightly, causing small deviations in the timing of the tip passing by a sensor.

A special proximity sensor detects the tip of the turbine blade, and can be based on optical, eddy-current, microwave, and other techniques. Any positional deviations of a tip from nominal give indications about the mechanical forces on the blade as well as compliance of the blade to those forces as the blade ages. Specifically, each blade has natural resonances and compliance, both of which can change if the blade cracks.

A turbine typically contains several stages and each stage contains many blades. See Figure 2 below for an example. The number of tip sensors per stage is variable; if blade twist is measured, at least two sensors are oriented perpendicular to the rotation direction. Also, the acquisition rate from each sensor is fast. For example, consider a stage with 60 blades, the width of each blade occupying about 1/10 the space between adjacent blades, and a generator running at 3600 RPM (60 Hz). The tip sensor would detect a pulse every 1/3600 s, lasting for less than about 1/36000 s, as the blades passed by. Accurate location of the pulse peak or zero-crossing then requires sample rates over 100 kS/s. Because multiple sensors are typically used, tip timing measurement systems can easily generate 10s of MBs of data per second.


Figure 2 – Example generator turbine blades

A good reference for the tip timing technique is described in the article by ITWL Air Force Institute of Technology – Poland, “Application of Blade-Tip Sensors to Blade-Vibration Monitoring in Gas Turbines.”

Remotely Monitoring Electrical Power Signals with a Single-Board RIO

Remotely Monitoring Electrical Power Signals with a Single-Board RIO

Electronics Design for sbRIO Mezzanine Card Combines Custom Needs with Flexibility

Client: A designer and manufacturer of leading-edge electrical power monitoring equipment.

Problem Scope

Smart Grid investment is growing. Two important premises for Smart Grid design are access to local power sources and an understanding of loads and disturbances on the grid at various locations. These local power sources are typically alternative, such as solar and wind, which have intermittent power levels. Since the levels fluctuate, an important feature of proper Smart Grid operation is handling these erratic supplies. Optimal understanding of these disturbances and load changes increasingly requires measurements on individual AC power cycles.


Local power analysis systems typically have constraints in equipment cost, size, and power usage balanced against the need for simultaneous sampling front-end circuitry and custom data processing algorithms on the back-end. Furthermore, many of these systems are presently deployed as prototypes or short-run productions, requiring a combination of off-the-shelf and custom-designed components.

Technical Highlights

A custom RIO Mezzanine card was designed and built for the National Instruments Single-Board RIO platform to provide access to simultaneously-sampled signals from the 3-phase and neutral lines of an AC power source. Timing synchronization between physically-separated installations was provided by monitoring GPS timing signals. Custom VIs were developed to retrieve the sampled data points and GPS timing for subsequent processing and analysis.



Figure 1 – Power Line Data Acquisition sbRIO RMC Module with GPS Timing

We needed 8 channels of simultaneously-sampled analog inputs (AI), each capable of sampling at least 50 kHz. These AI channels sample the voltage and current of the neutral and three phase power lines. Furthermore, to coordinate power and load fluctuations across many measurement locations, a world-wide synchronization signal is needed.

The Single-Board RIO (sbRIO) platform from National Instruments offers an excellent balance between off-the-shelf capability and custom design needs in a reasonably small package. The sbRIO provides the processor, memory, and connectivity while the RIO Mezzanine Card (RMC) provides the I/O and signal conditioning needs. See our white paper, Developing Embedded Systems: Comparing Off-the-Shelf to Custom Designs, for a discussion of the benefits of using this approach.

We designed the RMC for the simultaneously-sampled analog inputs and a GPS receiver. The RMC was mounted to a sbRIO-9606. Some design specifications were:

  • 8 analog input channels: simultaneous sampling at 50 kHz, ±10 V range, 16-bit resolution
  • GPS receiver with Pulse Per Second (PPS) timing signal with 60 ns accuracy
  • SMA Connector for external GPS active antenna
  • 20 position terminal block for analog inputs and shields, removable for wiring
  • Operates inside an enclosure with internal conditions -40 to 55 °C temperature

An image of the designed RMC and the sbRIO-9606 is shown below.  Since the A/Ds reside on the RMC, the data bytes are accessed by sbRIO FPGA VIs code communicating through an SPI data bus designed into the RMC.  The internal real time clock coupled with the GPS PPS signal allowed for timing accuracy within a GPS region well under +/- 1 uS of accuracy for all data sampled no matter the location, internally or from unit to unit within feet or 1000s of miles away.


The combination of the sbRIO off-the-shelf platform and the custom RIO mezzanine card (RMC) for I/O makes a powerful, cost-effective, and yet configurable solution for measurements of AC power signals. With the GPS component on the RMC, measurement units can be placed at dispersed locations while still providing adequate synchronization of acquired waveforms for localizing and understanding disturbances in power transmission and distribution, irrespective of any specific application. If you have an embedded monitoring application that you’d like help with, you can reach out to chat here.  If you’d like to learn more about our circuit board design capabilities, go here.

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Industrial Embedded – Industrial Equipment Control

Industrial Embedded – Equipment Control – VAR Compensator


Keeping the Electrical Grid Healthy with VAR Compensation


Modular Embedded System Shortens Development Time and Reduces Risk in Static VAR Compensation System


Client: T-Star Engineering & Technical Services: A manufacturer of electrical power delivery equipment.


The U.S. power grid is a large electrical circuit that, although has some amount of isolation between loads, is certainly interconnected at drop points, which is what customers care about most.

SVCs are generally worth considering in scenarios where large electric motors are being utilized (e.g. mills, recycling plants, mines). Problems such as voltage sag, voltage flicker, and current harmonics can cause reduced motor torque, lights to flicker, and equipment damage.


T-Star has significant domain expertise in stabilizing medium voltage power systems. Viewpoint has significant domain expertise in the realm of measurement and control systems. The team at T-Star needed a well-supported intelligent device for their new generation Static VAR Compensator (SVC). They wanted a highly reliable solution that had minimized the time-to-market and a highly predictable future migration path for higher volume production. They also needed multi-channel precision timing, and high speed logging in a device certified for operation in dirty industrial environments.


Viewpoint was asked to develop the controller for T-Star’s Static VAR Compensator (SVC) using a carefully constructed specification. The chosen controller platform is a National Instruments (NI) Compact RIO due to its modular feature set, networking capabilities, and associated supportability and quality that comes with an industrial-grade off-the-shelf controller. T-Star and Viewpoint have made very complementary GSD (Get Stuff Done) teammates.

As the grid gains intelligence, this class of smart/dynamic power quality system will likely become more critical.


Cabinets for an SVC located at a remote mine in British Columbia


Inside an SVC


  • The platform supports other future configurations that are outside the phase one scope of this project.
  • Time-to-market is critical for T-Star. The initial proof of concept was completed in weeks.
  • The Linux-based OS, well known in the embedded community, provides a rich ecosystem for enhanced usability (e.g. network stack), and real-time operation.
  • Secure access through VPN with built-in firewall and user account control and permissions allows for remote diagnosis, health monitoring, and gathering of online information.
  • An FPGA allows for deterministic timing and parallel processing.
  • With COTS hardware, future upgrades are simplified with code base reuse and recompiling for new hardware.
  • The NI platform provides a migration path to a lower-cost solution once hardware configurations are locked down and production volumes increase above a certain level.
  • The NI control hardware is certified (certifications in the domains of CE, FCC, UL, etc.) for marine applications and other challenging environments.

System Overview

The SVC tunes a highly inductive load by dynamically injecting a variable amount of capacitance due to the measured load. Voltage and current sensors feed a series of control algorithms which determine the voltage and current imbalance in order to inject the appropriate amount of capacitance into the power system. This algorithm acts on a cycle-by-cycle basis. The figure below illustrates the system makeup.


Embedded Control for Industrial Machine – Gear Lapper

Embedded Control for Industrial Machine – Gear Lapping





With the embedded control system that Viewpoint created using NI
RIO hardware and LabVIEW FPGA, our customers can increase gear
quality and save cost at the same time.
Mark Strang, Project Engineer, The Gleason Works


The Gleason Works sought to create a dynamic, torque-controlled lapping solution with responsive, realtime feedback to create better quality gears and reduce cycle time for its gear lapping machines.


Viewpoint Systems provided system integration using NI RIO technology and LabVIEW FPGA code for real-time measurement and control.


Gleason Corporation and The Gleason Works create the machines, tooling, processes, services, and technologies needed to produce the bevel and cylindrical gears found virtually everywhere – from automobiles and airplanes to trucks and tractors, and from giant wind turbines that can power a thousand homes to the lawn mowers and power tools found at these homes. Gear tooth surfaces and spacing are never perfectly machined, and consequently, noise and vibration are often present in applications where the gears are later used. Gears, after the typical heat treatment process, are commonly lapped or ground to smooth the gear teeth surfaces and improve operational characteristics. The goal of lapping is to reduce surface and tooth spacing deviations that may produce noisy gear sets.

Gleason machines lap gears in pairs, the mating gear and pinion members rotating together at a high speed with an abrasive lapping slurry applied. After machining and heat treatment, however, the spacing deviations that need to be lapped are at unknown locations on the gears and can show themselves as run-out (i.e., an off-center axis). To further complicate finding the deviations, the run-out is actually composed of multiple orders, likely making the run-out for each order different than the others.


One conventional approach to lapping employs machines with relatively high-inertia spindles to carry the gearset members. At moderate speeds, this configuration can somewhat reduce spacing errors during lapping, but is far from optimal in refining the tooth surfaces. Another approach employs at least one low-inertia spindle. This configuration can refine tooth surfaces well, but tends to increase spacing errors—especially at higher speeds. In both conventional cases, one spindle is operated in a simple constant torque command mode to control lapping force, but the critically important dynamic torque components are left to passive physics.

To get the best of both worlds, Gleason could no longer rely on passive physics, and turned to Viewpoint Systems to help develop and implement an embedded control system that could measure deviations in real-time and apply dynamic corrective torque.


With this new, patent-pending system founded on embedded control and dynamic real-time process monitoring technologies, Gleason and Viewpoint bring exciting new capabilities to a worldwide and well-established gear finishing process. The unprecedented ability to improve gearset quality during lapping, and to do so at higher speeds provides a winning market proposition—one made possible by intelligent application of today’s leading-edge technologies. With its new solutions, Gleason gear manufacturing systems now produce higher quality gears in 30 percent less time. Throughout the process, Gleason appreciated Viewpoint’s expertise and synergy achieved when working together. More than just an implementer, Viewpoint’s experts worked alongside their own to develop new techniques and solutions in an agile and collaborative environment.


Gleason engaged Viewpoint Systems to implement this real-time measurement and control system because of their expertise with the leading reconfigurable I/O (RIO) hardware from National Instruments. Viewpoint used the NI RIO technology and developed LabVIEW FPGA code to create a real-time measurement and control solution for the lapping machine. Viewpoint equipped an NI cRIO-9076 controller with an NI 9411 digital input (DI) module and an NI 9263 analog output (AO) module. The DI module monitors two digital rotational encoders, one on each spindle carrying the bevel gear set members. Innovative analysis of these angular signals can tease out subtle variations in the average rotational speed. Coupled with sophisticated order analysis, these variations are used to modify the torque applied to the gear set at the proper angular positions and with the appropriate amplitude. Thus, the high-frequency dynamic torque components experienced by the gearset during lapping are no longer dominated by passive physics, but are actively controlled to achieve desired results. Viewpoint created the system to manage all of the measurements, analyses, and torque corrections in the RIO FPGA with specific, efficient coding in LabVIEW FPGA using Viewpoint’s FPGA IP toolset. The cRIO controller provides data collection and even data archiving functions to support other advanced post-processing. The controller also provides an API to control the adaptive lapping process from a supervisory application.

Improving Efficiency in Industrial Manufacturing Test


Improving Efficiency in Industrial Manufacturing


Simplifying Report Generation for High-Mix, Low-Volume Industrial Servo Valve Tests


Client: A major industrial servo valve manufacturer


A manufacturer of components for both commercial and military aircraft built a large number of different models of servo valves. Some models were made only a few times each year, while other models were made with an order of magnitude higher volume. Each unit underwent rigorous testing during and after assembly.

Our client needed to submit the results of that testing to their customers but since the production and testing of each unit happened in many locations, possibly even around the world, many hours were spent locating the appropriate datasets and assembling the report.

Furthermore, our client wanted to improve their responsiveness to requests from their customers by having rapid retrieval of the test report for any part after it had been delivered into the field.


Since the test datasets were varied due to the large numbers of different valve models and associated test procedures, a database was created using a platform based on the Resource Description Framework (RDF). An RDF database can accept arbitrary types of data, manage that data through metadata tags, and adjust gracefully to changes in content and shape of the connections between objects in the database.

This adaptability was key to our client being able to leap past some of the issues in standard SQL-based relational databases.

The results from each test run on each part at each (PXI-based) test system were tagged with metadata and pushed into the RDF database. The StepWise platform interfaced to the RDF database by outputting XML content which was scanned by a routine created for the RDF database and converted into the RDF data and links. The part ID was a critical tag since this allowed searching the RDF database for all results associated with that specific part. This database resided on a server at the client’s headquarters and accepted data from worldwide locations.

Once the data for each part was housed in the database, a report could be generated. To accommodate the variety of data in that report, web technology was used to render the report pages based on the types of data entered into the database, as described by the metadata tags. For example, data identified as waveforms could be plotted or listed in tabular format. Having reports rendered based on the data types made it possible to handle adjustments to the types of data measured by the test system.


With the ability to render reports quickly, our client could produce detailed reports for their customers indicating the performance of any specific requested servo valve.

Our client was able to trim the time to create reports to less than 1 day from the previous effort of 3-5 days and with less error.

  • Data are now organized uniformly, simplifying the location of desired information, as compared with files stored on various test PCs and file servers.
  • The client has the ability to generate automatic emails to their customers with the required reports already attached and ready to go.
  • In potential warranty and customer service situations, having the ability to send the customer a report within hours represented great customer service.

All these features are available consistently across worldwide manufacturing facilities, reducing training and maintenance of procedures. And, of course, the reports handle using metric or English units as appropriate for the end customer.

Decreasing Test Time for Aircraft Landing Gear

Decreasing Test Time for Aircraft Landing Gear

Endurance Testing for Aircraft Nose Landing Gear Steering

Client: A major manufacturer of aircraft landing systems


A major manufacturer of aircraft landing equipment needed to develop a means of endurance and fatigue testing new designs for aircraft steering. The actuators involved in steering the nose landing gear (NLG) required precise and reliable control through thousands of steering cycles.

Control loops needed to be closed at faster than 1 ms.

Prior systems were handled manually without real-time control and monitoring.


Our customer designed and built a test rig to provide the hydraulics and environmental conditions for the endurance testing on the NLG. Viewpoint Systems supplied the electronic data acquisition and control hardware coupled with real-time software to provide the required fast control loops. The configuration and execution of the 1000s of steering cycles were managed by the same data acquisition and control system through a set of configuration screens that allowed specification of turn rates, min/max angles, drive and resistive torque settings, and so on.

  • The various PID control loop configurations were also configurable along with gain scheduling required under different operating conditions.
  • The environmental conditions were supported by controlling a temperature chamber through ramp and soak settings occurring during the steering tests.
  • Measurements on the steering performance were collected from commanded setpoints, sensor readings, and controller outputs during the entire test run.
  • Alarm and fault conditions, such as force exceedance, were monitored continuously during operation so that the system could safely run unattended.

The entire system underwent an extremely rigorous acceptance testing procedure to verify proper and safe operation.

Arbitrary Load and Position Profiles
Flight Position Control
Load Position/Force Control
Endurance/Flight Schedule Execution
Deterministic RT for DAQ and PID Control
PXI/SCXI Hybrid RT Chassis
Discrete Pump Skid Interface
Custom Control Panel/Console
Ethernet TCP/IP


Prior to deployment of our system, setup of a test was much more manual and operators needed to be around to monitor operation.

With our new system, complete endurance testing could be specified and executed with minimal supervision. Furthermore, the tight integration of real-time control and coordinated data collection made report creation much simpler than before.

The rigorous acceptance test gave trustworthiness to the data and allowed the design engineers to validate performance more quickly than the prior semi-automatic and manual methods of operation.

Setup of tests has been improved from prior operations. The endurance testing itself operated over a huge number of cycles lasting weeks to months between scheduled lubrication and maintenance.

The deployed system measures performance during the entire testing, even between the scheduled downtime.

Industrial Embedded Equipment – Leak Tester

Industrial Embedded Equipment – Leak Tester

Shortened Product Development Cycle for Industrial Equipment – A Leak Tester


Leak testing sounds simple. It seems like all you have to do is wait for the pressure (or vacuum) to drop by a detectable amount and estimate the leak rate based on the time it takes to reach that detected decrease. But, in an assembly line, it’s not, mostly due to the desire to do everything as quickly as possible.

Many manufactured products need to be tested for leaks to be sure they hold pressure or vacuum. Examples are fuel cells, braking systems, air bags, air conditioner components, balloon catheters, and so on. The list is almost endless.

Our client needed to develop a new leak tester with lower cost and more sensitivity and same small size.

Technical Highlights


The manufacturer wants the test to run as fast as possible – production volumes can’t tolerate a long wait to sense a leak. And, don’t forget, these products are not supposed to leak, so the “bad” ones leak very s-l-o-w-l-y. This is where the complexity in performing a leak test in a manufacturing environment arises.


The tester must be super-sensitive – to be able to sense a leak as soon as possible balanced by cost constraints and the need for the tester to be physically small so it fits on the production line


The tester needs to provide a solid user experience – so it needs to be robust and smart so the production test operator can just use it without hassle.


Our client had been building commercial leak testers for many years. Their development tools were built on in-house hardware designs and a software library for making measurements and interacting with the operator via buttons and a display.

The typical development cycle extended to over 1 year and they wanted to shorten that development timeline by utilizing more Commercial Off The Shelf (COTS) components, especially since embedded controllers had improved dramatically over the recent years, and they did not sell a huge number of these specialized product per year. Put another way, they were looking for a supplier that would pay better attention to them since they were competing for responsiveness from say the microcontroller vendors when those vendors were used to customers purchasing 100s of thousands of microcontroller per year. They were ready for a change in design tools and subcomponent vendors.

Another issue was the need for extremely accurate pressure detection (so the leak test could be fast!). They wanted to go with COTS components, but they could not find a COTS detection system (sensor and digitizer combination) with enough accuracy and responsiveness. They needed a hybrid approach of COTS for the controller and custom for the signal conditioning and acquisition I/O.


The prototype unit was designed, built, and ready for testing of the leak testing capability in about 2 months after the requirements were completed. The collapsed single-board solution was then designed, built, and unit tested about 1 ½ months later.


Leak Tester Sub-assembly and enclosure

The custom circuitry combined with some proprietary algorithms executed on the NI SOM RIO was able to measure with about 10 times better sensitivity than the previous generations. This sensitivity translated into faster leak measurement times – a real selling point to our customer’s customers.

The customer was ready to do their validation in about 4 months after we had the green light to build. The ready-to-go VERDI prototyping system was a huge time-saver.

Viewpoint’s Solution

We worked with our client to develop a system based on the NI RIO platform from National Instruments (NI). We initially considered the NI sbRIO but chose the NI SOM RIO (sbRIO-9651) because of its size and slightly lower costs.



After an initial review of the customer’s design goals and requirements, a concerted effort was spent to morph those goals and adjust those requirements by iterative discussion between both of our engineering teams. It was truly a collaborative requirements gathering and design activity. We brought our knowledge of the NI SOM RIO I/O and LabVIEW programmability capabilities and the customer shared their understanding of leak detection and their customer needs.


VERDI – Chassis with modules

Enter VERDI – Once the requirements and initial design were complete, we designed and built a custom A/D and signal conditioning circuit board that could interface with the NI SOM RIO. The initial version of this board was designed to connect to our VERDI prototyping system so we could rapidly validate the performance of the circuitry without needing to build the complete single-board system (with SOM and other circuitry all on one board).

After some tweaking to improve this custom circuitry, we essentially copied the board layout from all the necessary I/O (SOM controller board, digital I/O, display I/O, and the custom leak-detection circuitry onto a single-board system. This effort was reduced, since we had a large amount of ready-to-reuse hardware designs already developed for the VERDI prototyping system.

Industrial Embedded Monitoring – Remote Structural Health Monitoring using a cRIO

Industrial Embedded Monitoring – Remote Structural Health Monitoring

Using a cRIO to remotely assess structural health

By connecting these systems with a host PC, we can monitor continuous vibration activity and alarm conditions on a variety of structures despite inclement weather.


Continuously monitoring the structural health of the Long Island Railroad (LIRR) Viaduct despite the relative inaccessibility of the structure.


Using CompactRIO, LabVIEW FPGA, and the LabVIEW Digital Filter Design Toolkit to measure the modal analysis of vibration data generated from ambient excitation, capture this data remotely, and analyze significant events.


Engineers use structural vibrations to assess the conditions of many constructions and machines, including buildings, bridges, dams, towers, cranes, and mountings. Although we have had tools to monitor structural vibration for decades, these tools restrict data collection to short durations of high-fidelity waveforms or longer durations of summarized power in frequency band results. Many structures vibrate in meaningful ways only in the presence of ambient forces such as wind, vehicle activity, nearby construction, or random events such as earthquakes and tornados. Therefore, data collection needs to be active during these events.

Due to recent improvements in memory storage, processor speed, and wideband wireless communications technology, we can collect high-fidelity waveforms over long periods. We can also communicate to host PCs that aggregate structural vibration data across multiple collection locations, providing permanent data collection and superior analysis and reporting capabilities.

STRAAM Corporation, a leader in structural integrity assessment, and Viewpoint Systems, a Select National Instruments Alliance Partner, collaborated to develop a system that functions outdoors and in other less-accessible sites and maintains the capabilities of the available PC-based solution. Ultimately, we produced an enhanced version of STRAAM’s SKG CMS™ system to install on a Long Island railroad bridge.

 System Requirements

The system needed to perform the following operations:

  • Collect data from accelerometers and other environmental sensors
  • Store weeks of data locally at full acquisition rates
  • Analyze custom data in real time
  • Publish summary statistics periodically to the host
  • Upload waveforms to host on request
  • Offer rugged, lightweight, cost-effective, reliable OEM deployment
  • Contain flexible architecture to handle future capabilities
  • Ensure secure user access control

System Design

We chose a system based on the NI CompactRIO platform and dynamic signal acquisition (DSA) C Series modules. The CompactRIO and associated C Series signal conditioning modules have an operating temperature range of -40 to 70 °C, well within typical environmental extremes for most installation locations. Additionally, the CompactRIO controller has no moving parts, increasing the mean time between failure and ensuring it can withstand physical mishandling during shipment and installation. For software, we decided to use the NI LabVIEW Real-Time Module and the LabVIEW FPGA Module. We used LabVIEW FPGA for basic signal acquisition as well as some custom antialiasing filtering to allow for sampling rates below the capabilities of the DSA module.


Figure 1 – Equipment mounted to LIRR Support Beam

Data Acquisition and Filtering

The DSA module acquired acceleration signals via special sensors, supplied by STRAAM, that output information about tilt and acceleration. Because large structures resonate at low frequencies, it is important that these sensors have extremely low noise, high dynamic range, and low frequency response to gather information about structures at less than 1 Hz. The low frequency range and long-term data storage need combine to create a maximum data collection rate frequency of 200 samples per second (S/s). The NI 9239 does not sample that slowly due to its delta-sigma converter technology, so we sampled at 2,000 S/s and used lowpass digital filtering on the field-programmable gate array (FPGA) to produce an antialiased signal at 200 S/s. Simple subsampling through decimation would violate the Nyquist criterion. Using the LabVIEW Digital Filter Design Toolkit, we produced a 28-tap infinite impulse response (IIR) filter with a 3 dB roll-off at 0.8 times the sample rate with a stopband attenuation greater than 90 dB. The Digital Filter Design Toolkit includes tools to automatically generate code to deploy the filter to the FPGA. We carefully selected fixed-point arithmetic to ensure proper operation without using excessive FPGA resources. The final filter was a 24-bit fixed-point solution with a 4-bit mantissa.


Figure 2: Remote Front Panel Displaying Acceleration Waveform Capture

Configuration, Signal Processing, and Alerts

STRAAM uses proprietary analysis routines, based on the structure’s resonant frequencies, to extract relevant information from the continuous stream of acceleration data. Because ambient energy excites the structures, we analyzed some initial data to locate these resonances. After this initial period, we configured the CompactRIO to perform the proprietary analyses based on the location of these resonances. We handled all activity in this initial setup remotely via wireless communications. We connect to CompactRIO over a wireless connection, then to a LabVIEW remote panel where we initially acquire and assign resonance bands.

The signal processing requires the spectral power and time-domain structure of the waveforms inside those resonant bands. The CompactRIO processor and FPGA module can calculate fast Fourier transform (FFT)-based power spectrums and perform time-domain filtering calculation so we can base calculations on the complicated algorithms provided by STRAAM. Furthermore, the large CompactRIO RAM can archive raw acceleration waveforms for later retrieval. The LabVIEW development environment greatly simplifies adjusting these calculations. We apply additional calculations to identify noteworthy events to alert the engineers when important conditions occur. These conditions may signify the presence of a meaningful ambient excitation or that considerable changes to the structure have occurred.

Host Communication

In order to successfully operate, this system needs to communicate effectively to the host PC. Because the system is deployed in almost-inaccessible and outdoor locations, all interactions with the system should occur remotely. Using cellular modems, the system connects via TCP/IP to upload important information, issue event alerts, and allow remote configuration. We designed the LabVIEW application to send periodic summary information via custom binary messages to the host with information about the condition of the structure and the CompactRIO system. The host then tallies this information along with all other SKG CMS™ systems deployed in the field. In addition to this summary information, the host can pull raw waveform data from the CompactRIO RAM. To avoid tampering and unauthorized access, we password protected all connections.


Figure 3 – Data File Configuration Screen


We have successfully installed several functional SKG CMS™ systems based on the CompactRIO platform. By connecting these systems with a host PC, we can monitor continuous vibration activity and alarm conditions on a variety of structures despite inclement weather. Our customers enjoy the benefits of modern Ethernet-driven, Web-based connectivity to verify the status of their structures and we enjoy the benefits of the rugged, reliable, low-cost, and reprogrammable CompactRIO system for data collection.

Digital Record And Playback – For a RF Receiver

Digital Record And Playback – For a RF Receiver

Collect hours of data at >1 GB/s

Client: A large high-tech R&D-oriented company.


  • Record hours of data at >1GB/s
  • Play back digital test patterns for the RF receiver at real-time rates to understand bit-error rates
  • Understand effects of RF chain prior to digitization
  • Allow for platform to assist with algorithm development, debug and optimization


We utilized off-the-shelf hardware combined with custom software and had a working system after ~7 man-weeks of effort. The DRAP system records and plays back digital data only, with A/D conversion being handled by the DUT. The system was developed on the National Instruments PXI Express platform. A RAID array of disks is used to continuously record data. Data manipulation is performed on a Xilinx Kintex-7 FPGA that forms the basis of a National Instruments High Speed Serial board. The DRAP system is connected to the RF receiver using standard SFP+ connectors. A UI connects to the system locally or over Ethernet to monitor and control DRAP during record/playback. The customer can also control the system via an API so that it can be integrated into a larger test system.


  • Allows for repeatable data through the processing chain.
  • Can re-sample data, inject new headers into data packets, and re-pack new data.

System Overview


Check out DRAP »

Manufacturing Test System for Electrical Components

Manufacturing Test System for Electrical Components

Replacing Obsolete Custom Electronics with cRIOs in High-Power Capacitor Testing

Modular Embedded cRIO Systems Shortens Development and Reduces Risk in Complex PC-based Test System

Client: A major manufacturer of electrical power generation and distribution equipment.

Problem Scope

This project involved retrofitting a test system used to verify operation of a high-power capacitor used in electrical power distribution. This system was originally built around 1990. Critical sections of the original test system relied on custom, wire-wrapped analog and digital circuitry to process, analyze, and isolate the high-voltage and high-current signals created by the capacitor. Analog filters, rectifiers, and comparators produced pass/fail status signals. A master PC, other measurement and control equipment, the analog circuits, and a six-position carousel were integrated to create the entire automated test and control system.

For each unit under test (UUT), test specifications are obtained from a Manufacturing Execution System (MES) and cached locally. The subsystems at each carousel position are designed to run independently. This parallel capability allows greater throughput and reduced test time per capacitor unit. In addition, as different capacitor models move through the carousel stations, the test parameters and conditions must be aware of the particular model being tested.

Test results for UUT are pushed back to the MES system for record retention and data mining. The existing MES interfaces were retained exactly for the retrofit.


All capacitors require 100% testing prior to shipment, so the test system is critical for the facility operation. Two or even three shifts are common depending on production needs and the facility cannot afford any significant downtime. Thus, a challenge was to design and build a test system that worked and was very robust.

Another huge challenge was the lack of documentation on the existing system, requiring a sizable amount of reverse engineering to understand the test system operation before development on the new system could begin.

Furthermore, one of the most important challenges surrounded replacement of substantial amounts of original test equipment before the new test equipment could be installed. Thus, we absolutely had to minimize the time and risk in this upgrade changeover.

Technical Highlights


A schematic of the overall system architecture is shown in the figure. The major components of the system are:

  • Master PC for supervisory control and test execution management
  • NI cRIOs with FPGAs and Ethernet for independent yet PC-supervised operation
  • Station-specific FPGA code for replacing wire-wrap circuitry functionality
  • Integration with existing MES, safety equipment, tooling, and measurement hardware

The architecture chosen was made very modular by the capabilities offered by the cRIO. The Master PC interfaced with station-specific measurement instrumentation as needed, such as GPIB controlled equipment, and coordinated control and outcomes from the cRIOs. This additional equipment is not shown in the figure.


The Master PC coordinated all the activities including interfacing with the existing MES database and printers at the manufacturing facility. In addition, this PC provided the operator interface and, when needed, access to engineering screen on a diagnostic laptop.

The cRIOs were essential to the success of this test system. Each cRIO functioned as the equivalent of a high-speed standalone instrument.

The cRIOs at each carousel test position had to provide the following features:

  • Digital I/O for machine feedback, safeties, and fault conditions
  • State machines to coordinate with external commands and signals
  • Perform numeric calculations to emulate the old analog circuitry
  • Control loops for currents associated with voltages needed by different capacitors
  • Communication support with the master PC
  • Computation and detection of internal fault and UUT pass/fail conditions

We were able to duplicate the behavior of the wire-wrapped circuitry by converting the schematic diagrams of these circuits into FPGA code and then tweaking that code to mimicking the actual signals we measured with data acquisition equipment on the original test hardware.

The outputs of the circuitry were reconstructed on the FPGA with band-pass filtering, calibration compensation, point-to-point RMS, and phase & frequency functions. This functionality was implemented in fixed-point math and the 24-bit inputs on the A/D provided sufficient resolution and bandwidth for a faithful reproduction of the electronic circuitry. These embedded cRIOs provided a very effective solution to what otherwise might have required another set of costly and rigid custom circuits.

Finally, for optimizing the task of replacing the old equipment, we used a set of cRIOs, not shown in Figure 1, to provide Hardware-In-the-Loop (HIL) simulation of the manufacturing and measurement equipment. These cRIOs imitated the rest of the machine by providing inputs to and reacting to outputs from the embedded cRIO controllers, thus supporting comprehensive verification of the new test system before the tear-out of the existing hardware. Furthermore, these HIL cRIOs enabled fault injection for conditions that would have been difficult and possibly dangerous to create on the actual equipment.

Yes, I need a manufacturing test system »

Viewpoint’s LabVIEW Real-Time Application Development Tools

Over many years and many projects, Viewpoint has developed a set of internal tools that provide the functionality required for these types of applications. While each application is different is some ways, the tools for shelling out the framework are by and large reusable.

When developing the various types of data acquisition systems, it is not uncommon to have requirements for deterministic task execution for tasks such as PID Closed Loop Control, Digital Communication, and other operations. Since Windows is not a platform we can use to attain true determinism, we often utilize the capabilities of a National Instruments RT (Real-time) Controller and/or FPGA device.

Since these applications require both host side (Windows) and the deterministic side (RT), there is an inherent need to bring the two together.

These tools encompass the following areas of need:

  1. TCP/IP Connectivity for Command/Data Transmission
  2. HOST side Data Recording and Circular Buffering for global data access.
  3. RT side Non-Priority Loops (NPL) for low priority activity (processing host commands, etc.)
  4. RT side Time Critical Loop (TCL) for the DAQ Read, Process, DAQ Write activity

The figure below shows a visual description of the connectivity between the components as well as some common activity performed in the various locations.

The essence of the architecture is the data vector, which can contain all data involved in the application, including, but not limited to:

  • Analog Inputs/Outputs (Beginning of TCL)
  • Setpoints
  • Calculated channels
  • Digital Inputs/Outputs (End of TCL)

Some common tools we use in the RT layer include:

  • E-STOP Monitoring
  • Limit and Threshed Checking
  • Watchdog Timers
  • Function Generators
  • PID Closed Loop Controls

Note: All of these items are evaluated typically at 1kHz, but higher speeds can be achieved and are application dependent.

When even higher speed determinism is required, we often incorporate FPGA devices into the system. Viewpoint has a library of IP that we regularly utilize for common tasks such as Frequency/Period Measurement, LVDT Demodulation, Digital De-bounce/Deglitch, Encoders, SPI, and custom UART interfaces, etc.

With an FPGA, the deterministic speed capability is significantly higher and results can be passed directly to the RT layer though DMA FIFOs.

On the host side, we have an equal set of companion tools to interface to the RT layer and manage the data for the host application. This includes:

  • Circular Buffering of Data Vector
  • Command Sets allowing direction of activity on the RT side and setting output values.
  • Hardware Abstraction Layer for RT interfacing, as well as other, non-RT instrumentation such as DMM, Power Supply, and Environmental Chamber control.
  • Data Recording with decimation.
  • Diagnostic Panels with digital and chart presentation.

These tools provide an environment for rapid application development. While these tools can be used for any application approach, they are quite often utilized in conjunction with StepWise; a VSI platform for sequential test step execution and reporting.

Together, the StepWise platform, combined with the RT Toolset provide complimentary functionality for demanding custom test and measurement, control, and R&D applications.

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