DMC developed a LabVIEW application that allows flexible test sequencing across different test stands. In addition, we integrated generic PC peripherals with the LabVIEW application to ensure that high-level functionality of common interfaces (Ethernet, USB, and Serial) was verified. Pairing precision instruments with everyday IO in a custom test sequence allowed for end-to-end product testing and was made possible by the NI TestStand development platform.

The test system is also fully integrated with a Microsoft SQL server database to ensure compliance with modern production requirements. Database-level traceability, especially in the automotive industry, allows manufacturers to confidently and securely store production data with ease of recall for internal reporting or external audit. SQL offers an extensive toolchain for custom data analysis and process performance analysis to ensure the system continues to run reliably throughout its lifecycle.

PCB function test systems are prevalent in modern production environments. Today, Embedded PCB devices have many sub-systems, so achieving complete test coverage with automated test solutions can be demanding. By utilizing a flexible hardware design, customizable software technologies, and partners with the expertise to integrate the system components, manufacturers can ensure a highly productive and effective path to delivering high-quality products.

Learn more about DMC’s Test and Measurement and Embedded expertise and contact us for your next project.

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The test stand is capable of integrating with external measurement equipment over USB, GPIB, serial (RS-232), and Ethernet, allowing test sets to adapt to future calibration requirements. Additionally, the calibration test stand features several extra PXI slots, allowing additional instruments to be added as test requirements change over time. The mobile calibration test stand is approximately four feet tall, two feet wide, and three feet long.

The system’s condensed size allows it to easily traverse through doors and move from building to building to access a diverse set of equipment and sensors it is responsible for calibrating. In addition to designing and fabricating the hardware, DMC also created a custom LabVIEW application to view and monitor live data, record data, and generate a calibration report.

3D model of the mobile calibration test stand

DMC’s Fabrication Studio team assembled the mobile calibration test stand in-house

Custom Hardware

DMC designed the custom front panels that secure the programmable power supply in place and provide a mounting surface for DUT and auxiliary connectors to plug into the system.

DMC designed a custom PCB mounted on the inside face of the bottom panel. The purpose of the PCB is to route signals and simplify the system’s internal wiring. This PCB was designed in-house by DMC’s Embedded Development team.

Plan for the Future

The system was designed with the future in front of mind. It was important to the client to be able to adapt to new products and changing test requirements. To help achieve this an 18-slot PXI chassis was used in the system allowing several slots to be reserved for future use. The system interface was designed to allow for maximum adaptability. Banana connectors allow the client to connect to DUTs or external test equipment with non-standard interfaces and the bulkhead USB, GPIB, serial, and ethernet (RJ45) connectors allow the client to connect new models of measurement equipment across most commonly used communication protocols.

In addition to the hardware, the LabVIEW software was designed in a way the client could expand beyond the original project scope and add support for new calibration measurement devices by using a hardware abstraction layer (HAL) and measurement abstraction layer (MAL). The HAL and MAL help simplify future code additions, allowing the client to maintain complete ownership of the codebase after its initial deployment.

Built In-House

Our Control Panel Design and Fabrication team from the DMC Fabrication Studio built the test system in-house. The enclosure encompasses a rugged 14U rack system, which allows the PXI chassis, power supply, custom signal routing PCB, and DUT interface connectors to be easily mounted. A lockable shelf at the top of the rack provides storage space for the system laptop and any testing accessories while not in use. Large rubber casters allow the system to roll indoors and outdoors to service different buildings throughout the client’s campus. The external DUT and auxiliary device connectors are secured to the front face plates, while the measurement and switching equipment are slotted into the PXI chassis near the bottom of the rack.

Conclusion

DMC leveraged the expertise of many of our service areas to design, build, and deliver a new and improved calibration system for the end client. The Test and Measurement Automation team led the overall design, the Embedded Development team designed the custom PCB, and the Control Panel Design and Fabrication team was responsible for the final assembly of the system.

The upgraded test system allowed the client to increase calibration efficiency, accuracy, and allow for room to expand the system’s capabilities in the future. DMC developed a LabVIEW application that can be expanded upon by the client and they are able to maintain complete ownership of the system after final delivery and acceptance testing.

Our extensive experience with LabVIEW programming, developing Test and Measurement Automation systems, and building turnkey solutions qualified us to deliver this modernized system and successfully upgrade the test equipment to meet the client’s present needs while making provisions to enable future enhancements.

Learn more about DMC’s LabVIEW Programming expertise and contact us for your next project.

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Key requirements included:

• Longevity and Support: Utilizing PXI modules and Ethernet-based communication with an LXI mainframe, the system is designed for a lifespan of 15 to 20+ years.
• Reliability and Fault Detection: Components were selected for their reliability and ability to detect faults early in runtime operations.

Recognizing that standard COTS switches alone were insufficient, we collaborated with Pickering to extend the PXI-based switching portfolio. This collaboration resulted in the custom development of the 40-619 series switching modules to meet the precise specifications required, including direct contact state monitoring and relay fault detection.  

Additionally, Pickering enhanced the safety and reliability of our test solution with: 

• 60-103B-002 LXI Modular Switching Chassis – A modified chassis with an added safety feature to asynchronously force relays open upon system fault conditions. 

• 40-792 Series PXI 2MBit/s 75Ω Tributary Daisy-Chain Switch – A modified COTS switch product providing optimal topology for switching 75Ω impedance-matched communication signals.

To mitigate risks posed by the operating environment, Pickering conformally coated all modules. The chassis’ unique “failsafe mode” feature forces all relays to their open state upon receiving an external signal, protecting the test system by disconnecting the DUT from the test equipment during external faults. 

This solution offers high channel density, resulting in a compact footprint compared to competitors. Superior impedance matching ensures signal integrity, avoiding disruptions that could lead to poor test results. 

DMC’s longstanding relationship with Pickering, combined with our expertise in PXI and switching, sets us apart. Our engineers are committed to collaborating with customers to develop solutions tailored to their specific needs, ensuring all ATE system requirements are met. 

Learn more about our Test & Automation Solutions for Aerospace & Defense and contact us today for your next project.

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Test Specification

The functional test specification required:

• BMS firmware flashing
• Cell emulation
• Thermistor emulation
• Temperature and voltage tests
• Communication over CAN and serial buses
• Analyzing LED status indicators

Each BMS test results in a report with metadata identifying the DUT, test system configuration, and test results with limits included.

Systems Engineering

DMC had to factor in many requirements including test accuracy, cycle time, operator ergonomics, and overall system envelope. DMC leveraged our internal fabrication shop and carefully selected external vendors like Pickering for robust hardware solutions. The software design leaned on DMC’s existing platforms and tools to minimize costs while maintaining performance and reliability.

DMC divided the hardware design into modular sub-systems: data acquisition box, Bed-of-Nails test fixture, and instrument rack. The rack design housed multiple Pickering LXI chassis containing cell simulation and thermistor cards. The interfaces between these sub-systems were well defined early in the design process, along with consistent communication to minimize design siloing.

Software Design

Software customizability was a major consideration for the client, DMC built upon its proven Battery Production Test (BPT) platform to meet client’s software requirements. Some highlights include:

• Intuitive user interface and user experience design
• Customizable test sequences through NI TestStand
• Traceable reports with MES integration
• Tracked and version-controlled test configurations (workspaces)

Conclusion

DMC delivered a robust and highly configurable system on a deadline, providing our client with BMS test capability ahead of their full battery pack assembly line. The solution detects manufacturing defects and provides traceable test results to each battery under test.

Learn more about DMC’s Battery Production Test (BPT) System, check out this BMS Power HiL Test System, or contact us to discuss your next project.

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DMC started this project with a clear request to provide a BPT-based system within the Client’s strict budget.  DMC carefully analyzed their battery pack design, interfaces, and operating modes, and their overall testing requirements. This analysis revealed that the Client’s battery pack interface was relatively low-complexity, and their initial testing needs were rather basic. Since their requirements did not necessitate the use of DMC’s more full-featured BPT composition (see this case study), we initiated a new, lower-cost design, leveraging existing DMC hardware control modules. The result was a simple modular concept for achieving the basic battery pack tests that this Client required, while also meeting their aggressive budget demands.

This basic, but very cost-effective, BPT implementation allowed the Client to optimize use of their capital budget by purchasing only the test capability they needed for their current product. However, since this solution leverages the BPT platform software and NI hardware, they can still achieve the flexibility required for later expansion if needed.

Hardware System

To achieve this new BPT design, DMC leveraged the modularity of the NI platforms that form the basis of the BPT software and hardware system. Switching out the more capable, but also more costly, NI PXI systems for very cost-competitive NI cDAQ platform modules was easily accomplished with the NI DAQmx interface. DMC quickly transitioned our larger and more flexible BPT Low Voltage battery pack interface to a more basic one for control of all the required interfaces of a typical automotive battery pack: Vbat, IGN, GND, HVIL, CAN (see Figure 1). Similarly, DMC converted our larger and more complex ‘High Voltage Contactor Module” into the smaller and simpler sub-system shown in Figure 2.  While the resulting hardware system would have easily fit into a smaller test system rack, the Client wanted to reserve room for future expansion and selected a 36U high test rack, as shown in Figure 3. 

Software System

While the BPT hardware system was optimized for cost though selective hardware design, the software system of BPT was simply expanded to allow full control of the new low voltage and high voltage hardware sub-systems.  As such, users of this more cost-effective BPT system still have full access to the rich BPT software feature set, and full testing capability, including:

• Test Execution Management.
• Test Sequence programming using NI TestStand (Figure 4).
• Automatic and Manual run modes (Figure 5).
• Control of DMC hardware modules using pre-configured TestStand Custom Steps.
• Easy to use NI XNET CAN interfaces.
• Automated and customizable Test Results Reporting.
• Optional Custom Overview and Data Display Screens (Figure 6).
• Optional System Link integration. (Figure 7).
• Optional MES and Server Integration.
• Optional interface for common PLC communication protocols.

Conclusion

This new BPT model perfectly fit the Client’s battery pack test requirements, and their business needs:  Providing maximum test value, with optimized capital spend, and room for future expansion.

Learn more about DMC’s Battery Production Test (BPT) System and Custom Battery Pack and BMS Test Systems or contact us to discuss your next project.

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Six stations are used on the manufacturer’s two production test lines. Each line of three BPT stations shares one bank of NHR cyclers operating in parallel. A high power multiplexing (MUX) panel allows for this cycler sharing and includes infrastructure for each line to be expanded to by an additional station, allowing for up to four stations per line. The seventh station is a dedicated rework station.

High level overview of a single production test line where a MUX Panel allows up to four BPT stations to share a single bank of cyclers. DMC Delivered two of these test lines.

High level overview of Rework station, where the BPT station is connected directly to a dedicated bank of cyclers.

DMC provided additional custom hardware features, including a High Power Contactor Panel design that meets the specific needs of the client’s battery pack, and custom software features, including integration with the client’s manufacturing execution system (MES) to manage test execution and report test results.

Functional End of Line Tests

The BPT platform leverages NI TestStand to run a suite of production test sequences. For this application, the functional test sequences DMC developed include:

• BMS communication check
• Firmware flash
• Low voltage current check
• BMB communication check
• BMS sleep current check
• Pressure sensor check
• Brick voltage check
• Temperature sensor check
• Humidity sensor check
• Pack current sensor check
• BMS addressing check
• HVIL functionality check
• Contactor weld check
• Contactor control voltage check
• Pre-charge with open load check
• Pre-charge with shorted load check
• Pre-charge with good circuit check
• Isolation resistance check
• Induced isolation fault test
• Internal CAN check

In addition to the functional tests, DMC also developed sequences that utilize the NHR cyclers. These sequences include:

• Burn-in discharge test
  • Run at the end of the functional tests
  • Discharges pack at peak rated current for a relatively short duration
  • Measures electrical losses and thermal performance at maximum power delivery
  • Discharges pack to shipping state of charge (SOC)

• Charge to build SOC
  • Charges pack back to build SOC for retest / rework purposes

Cycler Sharing

DMC designed and implemented a high power multiplexing (MUX) infrastructure to connect a single bank of NHR cyclers to up to four test stations. This allowed the client to capture significant hardware cost savings, since a separate bank of cyclers was not required for each test station.

Overview of multiplexing design that allows up to four BPT Stations to share a single bank of cycler.

DMC designed the high power MUX panel with hardware lockout relay logic to prevent multiple stations from attempting to use the cycler bank at the same time. This lockout logic ensures that if a single station commands the contactors in the MUX panel to connect the cyclers to the station, the circuits to connect power to any other contactors coils are interrupted. Therefore, when a single station reserves the cyclers, no other stations can connect to the cyclers. Once a station finishes using the cyclers, it releases the cyclers and MUX panel so that other stations may reserve the cyclers.

Image of MUX Panel bus bar and contactor infrastructure.

DMC included a software configurable timeout to trigger an alarm and report to the facility MES system if a station waits too long to gain access to the cyclers. This feature allows the client to identify potential process improvements to ensure that packs are tested efficiently across the multiple stations on a single test line.

Additionally, DMC’s design allowed for the MUX panel to be included into the production test line’s emergency stop (Estop) circuit such that any one station can Estop the MUX panel (open all contactors) and cyclers, and the cyclers are able to Estop the MUX panel and all test stations.

Customized High Power Contactor Panel Design

Once a station reserves the cyclers and is connected to the cycler output via the MUX panel contactors, the station controls additional contactors within the High Power Contactor Panel mounted in the station rack to connect the cycler through to the battery pack under test.

Connection between bank of cyclers and battery pack under test via BPT High Power Contactor Panel.

The platform or “baseline” design of the BPT High Power Contactor Panel includes contactors that are used to make the final connection from the cyclers to the battery pack.

DMC customized this client’s High Power Contactor Panel to introduce other high voltage electrical components into the circuit, per client needs. In this case, the High Power Contactor Panel includes:

• Resistor-capacitor (RC) circuit
  • This RC circuit mimics the impedance of a vehicle powertrain inverter when connected to the battery terminals.
  • This circuit provides the necessary conditions for the battery pack BMS to accept commands to close its internal contactors.
• High current fuse
  • This high current fuse allows for a “short circuit pre-charge” functional test where the test stations close the appropriate contactors in the High Power Contactor Panel to short battery pack’s terminals across the fuse while the pack’s internal contactors are open. The station then attempts to command the pack to close its internal contactors.
  • The purpose of the test is to ensure that the pack’s battery management system (BMS) recognizes the short circuit and does not close the pack’s internal contactors when commanded while there is an unsafe short circuit condition.
• Polarity swapping infrastructure
  • The client manufactures multiple battery pack variants. On some pack variants, the battery terminals are arranged in a reverse polarity configuration.
  • The High Power Contactor Panel includes contactor and bus bar infrastructure to appropriately connect the battery terminals to the correct side of the cycler output according to variant polarity.
  • This infrastructure includes a lockout relay so that both polarity selections cannot be made at the same time.
• High voltage sense points
  • This variant of the High Power Contactor Panel includes six high voltage sense points that are connected back to the measurement matrix. This allows the voltage sense points to be measured by the system digital multimeter.
  • These high voltage sense points can be used to measure the voltage output by the cycler, measure the voltage of the battery pack, ensure the battery pack is connected with the correct polarity configuration, and verify the states of the various contactors in the High Power Contactor Panel for system self-diagnostics purposes.

Custom High Power Contactor Panel design.

MES Integration

DMC integrated with the client’s manufacturing execution system (MES) system to manage test execution and track test results. This MES integration utilizes the NI HTTP Client toolkit to interact with the client’s REST API.

Test Execution Management

Upon entering a test mode, the BPT system queries the client’s MES to determine whether sample testing is required. This allows the client to define a set schedule on which sample testing must be performed. For example, the client may choose to run a sample test at the beginning of each shift, day, week, etc. If sample testing is required, the BPT system alerts the test operator via a popup dialog.

The test operator is then prompted to scan the barcode on the pack under test. The BPT system parses the barcode to extract the serial number of the pack under test and queries the MES to determine whether the pack is ready to be tested. If the pack is not ready to be tested, the operator is alerted via popup dialog, and the test is terminated. If the pack is ready, the operator is allowed to continue with the test. The sequence to be run on the pack is automatically selected based on the pack part number, which is also parsed from the barcode scan.

Test Results Reporting

In addition capturing test results in a TestStand report document, the BPT system collects and publishes test results to the client’s MES. Results include individual graded measurements, higher level test results (e.g., BMS communications check pass or fail), major test results (e.g., Functional Test pass or fail), and overall “global” test result (i.e., whether the pack passed all tests or failed).

Rework Station

In addition to this client’s six test stations for two production lines, DMC delivered a seventh test station to be used for testing battery packs that may need to be re-tested, repaired, or reworked. For example, if an issue is identified with a battery pack during the first pass of production testing, it could be pulled off the main production line and re-retested with a more detailed diagnostic test routine to identify the issue and determine a rework or repair strategy.

The rework station highlights the flexibility of the BPT platform. All seven of the test stations are identically built and run the same software. The stations include all the necessary hardware, signal capabilities, and software features to complete both standard production testing and rework testing. The BPT’s simple hardware configuration capabilities and its Manual Mode feature enable this flexible testing.

Hardware Configuration

Since this rework station has its own dedicated bank of cyclers, the software includes a simple method for specifying the hardware configuration using TestStand Station Global variables. These are used to determine whether a station has its own dedicated cyclers or shares cyclers so that the cycler sharing logic can be included or omitted accordingly.

Manual Mode

Another software feature that is particularly valuable for rework testing is the Manual Mode test mode. Notably, only users who log in with advanced credentials can access Manual Mode. Standard users do not have access to this feature and can only run tests in Auto Mode.

As the name implies, Manual Mode allows an advanced user to interact more manually with a connected battery pack, as opposed to just running the pre-determined test sequence. Key features of Manual Mode include the interactive System State diagram and the Device View.

Interactive System State

The System State provides a convenient interface to view the current state of the system’s hardware. The System State includes:

• User-configured signal aliases
  • Allow the user to assign logical names to physical pins.
• Connector pins
  • Provide pinout information to correlate user-configured aliases with physical pins.
• Relay controls / indicators
  • Display the current state of relays at any given point during a test and allow the user to manually control relays.
• Instrument connection points
  • Show how the system instruments are integrated with the switching infrastructure.

The visualization of this information allows users to quickly understand the current configuration of the system and the possible paths that can be achieved with the BPT’s flexible switching infrastructure.

In Manual Mode, the System State diagram is interactive such that a user can click to command the various relays in the system to make pathing connections for diagnostic purposes. Additionally, in Manual Mode, the user can directly command the instruments in the system using the Device View.

Interactive System State.

Device View

In Manual Mode, the Device View allows the user to drag and drop soft front panels for the devices in the system. This functionality allows the user to build their own custom device “dashboards” to monitor and control the state of the instruments in the system.

As a simple example of how the user could leverage Manual Mode for diagnostic-style testing, the user might command relays on the System State to connect a battery pack signal to the system digital multimeter and then use the digital multimeter soft front panel in the Device View to measure voltage on that signal line.

Conclusion

DMC built upon the flexible Battery Production Test platform to deliver seven turnkey test stations. The standard battery test capabilities of the BPT platform in combination with the hardware and software customizations DMC implemented for client-specific requirements enable the client to efficiently and reliably test their electric vehicle battery packs.

Learn more about DMC’s Battery Pack and BMS Test Systems and contact us for your next project.

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The manufacturer approached DMC as soon as they identified the basic needs and challenges and chose us based on our demonstrated knowledge and experience testing similar products in the electrification sector.

DMC first took on a consulting role, leveraging decades of test engineering and technical expertise to collect and assess their requirements. Then, we collaboratively balanced the project tradeoffs (schedule, budget, risk, quality) against the technical performance of the new test system: resulting in a well-informed test specification and a conceptual test system design.

This collaborative ‘design phase’ quickly set up the entire project for success. The design phase uncovered several hidden requirements upfront, which resulted in faster convergence on the best test solution and allowed for continuous improvement with the flexibility to incorporate more complex quality assurance testing when they are needed.

The following ‘design/build/deploy phase’ used DMC’s standard ‘turn-key’ project process, resulting in the successful deployment of the client’s new automated test solution in their production facility within a few months.

Technical Details

The client’s product was designed to safely store hundreds of kilowatt-hours of energy in an internal battery system and provide that power to users in a variety of AC-power formats through several physical outlet options. It also featured a user-friendly touch-panel display for configuring the AC power output.

In their previous manual process, testing these units required operators with technical expertise, physical dexterity, and test instrumentation skills. The manual testing process involved taking numerous measurements to ensure they met specific manufacturing standards while repeatedly interacting with various knobs and switches in a predefined manner. It also involved the risk of manual probing into a high voltage receptacle.

Test System Architecture:

DMC physically assembled high-speed and high-precision instruments into a small-form-factor test rack, along with an industrial PC and peripherals, an AC power distribution unit, and a single main test signal distribution/breakout panel. The industrial PC acts as the single test controller and communicates with test instrumentation through a variety of communication busses (Ethernet, RS232, USB).

Test System Hardware:

Pickering High Voltage Multiplexer: Instead of requiring an operator connect and disconnect various parts of the test system with the high voltage connections of the device under test, a set of Pickering high-voltage, relay-based multiplexer cards were housed in an LXI chassis and used to automate the voltage switching functions. This allowed a custom software layer to manage all the switching connections.

Keysight DMM: Making accurate voltage and resistance measurements in quick succession meant using a robust DMM that could handle such usage. Selecting a benchtop-style instrument, connected over ethernet using the LXI standard, allowed DMC to strike a balance between performance and cost. As a bonus to having a highly-flexible DMM integrated into the system, DMC designed an automated self-test sequence: which used the DMM to verify the health and integrity of the test system itself.

NI-XNET Interface and NI cDAQ: To monitor for faults and unexpected behavior, the test system listened to the machine’s internal CAN bus using robust NI XNET hardware integrated into a cost-conscious NI cDAQ chassis and connected to the PC controller over ethernet.

Test SystemSoftware

NI TestStand: To allow the client’s test engineers to quickly modify test sequences, or develop new ones, we created custom test steps that allow drag-and-drop usage and rearrangement within the intuitive and powerful interface that TestStand provides. The built-in test report functionality of TestStand was also utilized to produce customized reports for every device tested.
 
Operator Interface: DMC’s leadership in the Test & Measurement industry comes with plenty of internal tooling, which saves development time and associated costs for customers. One of these tools is LabVIEW code that provides a simple user interface which connects to TestStand, presenting a simplified HMI experience for operators. The system allows for different types of products to be tested with different test sequences by simply scanning a barcode on the product prior to starting a test run.
 
Python Drivers: The DMC software team used the inter-operability features of TestStand to call Python hardware drivers. Python allowed the DMC team to easily integrate publicly available and instrument vendor provided packages, merge code, and review code from multiple developers. This freed up the team to focus on simplifying the end user experience with easy-to-use test steps that included signal multiplexing and instrument acquisition.

End Result

DMC’s system design effort automated nearly every step of the new testing process, reducing operator steps and limiting the client’s exposure to energized high-voltage connections. The test solution continuously monitors for issues, faults, and unexpected behavior within the product’s internal control system. A clean and simplified test interface allows operators to focus on quality, following clear, specific instructions to interact with the machine’s front panel, reducing the risk of errors, and significantly speeding up the testing process.

While the previous manual test system took 1.5 hours per unit tested, the new automated test system can complete a full product test in under 2 minutes. Every aspect of the test process, from checking the CAN bus for faults, probing every electrical outlet for proper voltage, or running load tests, is now fully traceable, accurately recorded, safer, and faster with the new DMC test solution.

Learn more about DMC’s Automated Test Stand Design services and contact us for your next project.

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Our client had about a dozen identical data acquisition test stands deployed on their production floor that each executed a test sequence on a product and saved a data file locally to the PC. All of the data was saved long-term on each test stand, which made it difficult to retrieve data from a test stand or compare data between multiple. This also made them susceptible to data loss if a test station PC or a hard drive fails.

DMC had to take a different approach, as we did not have the option to modify the test software directly to save the data to a central location rather than its C Drive. This was because the extensive validation for the customer’s custom testing software had already passed, and they did not want to repeat the validation process.

The customer was seeking a solution where the data from all test stations would be stored in one central location so that data from any test runs from any station could be quickly retrieved and analyzed.

Python Windows Service

As we were not allowed to modify the test software directly, DMC wrote a Windows Service in Python that automatically moved new data files from each test stand to the SystemLink server.

The service is installed on each test stand and monitors a particular directory on the test stand’s C Drive for new data files. When new files are found, the service uploads them to the SystemLink Server using the server’s REST API.

SystemLink Systems Manager

The service was packaged into an NI Package using NI Package Builder. Using SystemLink’s Systems Management module, this NI Package was remotely installed on each test stand using SystemLink’s web interface. This installation included registering the Python application with Windows as a Windows Service so that it is always monitoring for new data files.

SystemLink Data Plugin

The raw data files from each station were custom-formatted CSV files. Each file could store different information about the test and any number of different test steps — which would make directly comparing data from CSV files difficult.

SystemLink Server facilitates the transformation of custom file types and formats to a common TDM format using DataPlugins. After conversion to TDM, data can be much more efficiently searched.

DMC wrote a custom DataPlugin in Python that converted the client’s custom-formatted CSV files into TDM files. Any CSV data file that is uploaded to the SystemLink Server would automatically be transformed into the friendlier TDM format.

Analysis Automation Script

After converting that test data into a common TDM format, DMC created an Analysis Automation script that automatically triggers for incoming data files. The automation script extracts test metadata and a list of “steps” that were executed for the test from the TDM file. Then, this information is sent to SystemLink’s Test Monitor module using the Test Monitor REST API.

Test Monitor facilitates several useful functions for an engineer who may want to view past test results from a web browser:

1. Write queries to search for specific tests using test metadata (date and time, serial number, part number, operator, test station, etc.)
2. View a list of steps and step results for a specific test
3. Generate dashboards or reports for a quick view of the overall status of the testing systems.

Long-Term Storage

Raw CSV and processed TDM data files are saved long-term on the SystemLink server. These files are directly linked to their test in Test Monitor so that original test data files are easily accessible, searchable, viewable, and downloadable.

Learn more about DMC’s Test & Measurement solutions, and contact us today for your next project.

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Multi-up Flashing System

The multi-up flashing system, capable of flashing four ECUs at one time, provides higher line throughput than the previous manual process. The test sockets run independently: allowing for different ECU models to be flashed at the same time.

Software Interface

Through DMC’s expertise in both LabVIEW and NI TestStand, we built a software interface between them to provide a unified solution with an operator-friendly user interface (LabVIEW) and a powerful, customizable sequencer (NI TestStand). This was done to satisfy the requirements of both end users: operators and engineers.

The LabVIEW user interface (UI) allows operators to know when a sequence starts or stops and which step they are at throughout the flashing process. The UI also guides operators through barcode scans to automatically select the right software to flash to the ECU.

NI TestStand’s sequence editor allows engineers to customize the flashing process for new ECU models and software revisions.

Hardware

DMC delivered three flashing stations that included PCs with hardware that will successfully ensure the ECUs meet a certain quality standard. The process is repeatable and traceable through NI TestStand reports and CAN logs for each ECU.

In summary, we created a high volume, automated, flexible flashing station that allows the customer to quickly modify and customize their own flashing sequences for existing and future ECUs.

Learn more about DMC’s Test and Measurement Automation expertise and contact us to get started on your next project.

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DMC reviewed the existing design and requirements for additional tests and worked with the client to implement them on their test stands. DMC updated the PLC test sequence and interface to include the additional tests.  Additionally, DMC upgraded the communication DLL integrated into the SoftPLC to fix several stability issues when communicating with the appliance under test.

The client was able to successfully integrate the new products into their process as well as improve testing efficiency.

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