Customer Solutions

by V. Arunachalam, Sr. Project EngineerKarthik Nanjappan, Project EngineerP. Saravana Kumar, Project EngineerK. Swaminathan, Business DevelopmentManager, Soliton Automation Pvt. Ltd.

The Challenge: Developing a HighlyAccelerated Stress Test system (HAST) in theshortest possible time for independent,simultaneous endurance testing of two X-raysystems controlled by CAN and serialcommunication.

The Solution: Creating an integratedsystem using the PXI platform with multiportCAN interfaces and serial interfaces forcommunication with the different X-ray systemsand high speed digitizers to acquire the faultwaveforms.

IntroductionOur customer, a leading manufacturer of X-ray system components for medicalapplications, designed new varieties of X-ray tubes for different applications. After the customer designed the new X-raytubes, they needed to test the new X-raysystem for endurance and validation beforetransferring it to manufacturing. The criticalHAST testing involves exposing the tubes to X-ray cycles of varying intensity andduration continuously for up to ten days and validating the various design parameters.The HAST provides valuable information tothe design team on the system’s reliability,

performance, and design validation. After we completed the design and defined thevalidation parameters, our customer asked us to develop a HAST station in the shortestpossible time to simultaneously test two

X-ray tubes. To fulfill the complexrequirements, we decided to use an integratedsolution and chose the PXI/LabVIEW system.

System RequirementsOur customer needed to control each X-raysystem through CAN communication to setthe exposure parameters according to testprotocols. With a serial interface to eachX-ray system, our customer could read the

values measured by themanufacturer’s measurementsystem, which we used tovalidate the system. We usedan additional serial interfaceto each generator for faultmonitoring and resetting the system after a fault.

Additionally, we validated the X-ray tubesbased on the occurrence of ‘spits’ or arcingcaused by dielectric breakdown in the X-raytube. We measured and recorded thetemperature at specified locations on the

X-ray system. The systems also requiredalarms and safety interlocks through software.

System DescriptionThe PXI instrumentation platform integrated all of the desired functionality tosimultaneously and independently performHAST on two units at a time. We used a two-port PXI CAN interface for CANcommunication. A four-port PXI serialinterface provided serial communication withthe test system and the X-ray measurementsystem. Four 100 MHz PXI oscilloscopesperform the high-speed data acquisition of spit waveforms from the anode and cathode of each X-ray tube. FieldPoint thermocoupleand discrete I/O modules measure temperatureand implement safety interlocks respectively.The system interfaces to a PC using a MXIinterface. A LabVIEW application controls the overall tests and data management. Thetest system interfaces to a second PC runninga Web server and a database.

Industry: R&D/Lab AutomationProducts Used: FieldPoint™ • LabVIEW™ 6i • NI-CAN™ • PXI

X-ray system with tube under Test

MeasuringSystem

MeasuringSystem

SerialCommunication

PXI Platform

CAN

High SpeedData

FieldPoint Bank forTemperature Measurement

and Safety Interlocks

MXIInterface

System PC

Web & Database ServerInternet

A Schematic Representation of the HAST System

Integrated PXI System for Multihead X-ray Tube Stress Testing

We easily integrated PXI, FieldPoint, CAN, high-speed DAQ, multi-port RS-232, temperaturemeasurement, and the digital I/O required for the system.

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Customer Solutions

System DevelopmentPowered by LabVIEW and the appropriatedrivers from National Instruments, we quickly developed the multiple CAN and serial interface communication. The customerused the simple user interface to define thetest parameters and view the results.

The spit detection posed a tougherchallenge. A spit characterizes a sudden dip in the applied voltage to the X-ray tube. Spits can occur at two positions (anode andcathode) in each station, simultaneously orseparately, and at any time during theexposure. This meant that the customerneeded the ability to trigger on any of thefour channels when a spit occurred. Becausethe customer wanted the ability to resolve the spit waveform finely, we used four100 MHz PXI scopes to trigger on a fallingedge and used software algorithms todifferentiate between a spit and the end ofexposure. With the PXI architecture, weintegrated waveform acquisition and analysisto perform the necessary feedback control to

stop the test if the spits exceeded a preset limit.We monitored the temperature and safetyinterlocks for test chamber door status andincoming power using FieldPoint modules.

We uploaded the test data and the HASTsystem status information into a databaseserver running on a second PC using the SQLtoolkit. A Web server on this PC made thisinformation available to the global teamsinterested in this data. Authorized users hadthe access to shut the system down via the

Web. By moving the database andWeb server activity into a secondPC, we ensured people trying toaccess the system status and datawould not disturb the HAST. This was important because the PC running the HAST softwareperformed high-speed dataacquisition (DAQ) and analysis.Using the Enterprise ConnectivityToolset features, we programmedthe second PC to send e-mails tothe engineers on the test status,reports, and any critical events.

System BenefitsWe easily integrated PXI, FieldPoint, CAN, high-speed DAQ, multi-port RS-232,temperature measurement, and the digital I/O required for the system. The LabVIEWenvironment combined with NI driversoftware provided seamless integration andapplication development. The alternativedesign involved using four separate

oscilloscopes and two separatePCs for control of the X-raysystem – but this system would not integrate all of the required functionality.

With LabVIEW, wedeveloped the complex

application that used CAN, serial, and high-speed DAQ to meet our tight deadline.We estimate that we saved one man-year of development efforts compared to previousattempts to automate similar processes(especially the spit detection) using alternative methods.

By eliminating the high-end, stand-aloneoscilloscopes and integrating all functionality,we saved more than $30,000. In addition, wesaved space, which is always at a premium in

a fast growing manufacturing site. However,the most significant savings were from thequick completion of the project.

The Web-enabled system provided theglobal teams with access to the HAST statusand results online. Furthermore, with thefeatures of the Enterprise Connectivity Toolset,the customer could instantaneously e-mail or mobile phone message critical results.

ConclusionOur customer needed a reliable solutiondeveloped in a short time period. Thecombination of FieldPoint, LabVIEW, and PXI helped us develop a user-friendlysolution within a very short timeframe. The HAST station deployed within eightweeks and the customer ran the HAST andvalidated their product successfully. ■

For more information contactV. Arunachalam, Senior Project Manager,Soliton Automation Private Limited, Classic Towers, 1547 Trichy Road, Coimbatore – 641018 INDIA, Tel: +91 (422) 302374, E-Mail: arun@solitonautomation.com

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A Snapshot of the Test Interface to the HAST System

"By eliminating the high-end, stand-aloneoscilloscopes and integrating all functionality,we saved more than $30,000.

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