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THE PERFECT TEST BED AUTOMATION SYSTEM

The Wind Tunnel Control System (WTCS) is a flexible and very powerful automation system that is used for both large test beds, such as wind tunnels, and component test beds to test mechanical or electronic components. WTCS offers a consistent and process-safe management and execution of tests and flexibly and reliably integrates all the different subsystems and measurement systems of the test bed. It also provides interfaces to external test planning and data management systems like Werum's own HyperTest Boost or systems by other providers, to which it can connect seamlessly.

As to the connection of subsystems, WTCS supports common industry standards like MODBUS, ProfiNet, DoIP, CAN or LIN just like binary or text-based TCP and UDP protocols. WTCS offers full manual control of the test bed as well as comprehensive automation capabilities with test sequencers to control test procedures and monitoring processes. Test data is centrally recorded in common data formats such as CSV or TDMS. Automatic "post-test" analyses allow data sets of the automation system to be processed together with data recorded locally in the subsystems, to be stored in new formats or to be treated for use in reports.

 

AT A GLANCE - EVERYTHING UNDER CONTROL

WTCS is the central information platform for the test bed. As all components and subsystems are integrated, the data of all relevant parameters as well as calculated variables are available already at runtime for display, recording and automated sequence control. The user can clearly visualize all information and intervene in all processes. Comprehensive automations take many routine tasks off the user's shoulder, make processes more efficient and even enable the unattended, fully automatic preconditioning of the test bed.

AUTOMATION

WTCS comes with a "Basic" Test Sequencer and an "Advanded" Test Sequencer for the execution of test sequences. Depending on the requirements of a use case, the appropriate component can be selected for simple step chains up to extremely powerful test execution engines for highly complex test methods.

WTCS also offers further automation functions beyond this. For example, any desired parameter can be monitored for limit values and suitable sequences can be executed in response to limit value violations. The control of "post-test" data evaluations, report generation, the import of test orders or the transfer of result data to archiving systems run completely automatically.

EFFICIENCY

Test time on the test bed is very valuable and should therefore be used most efficiently. By largely automating all routine tasks and data exchange with global test and data management systems, WTCS offers the best prerequisites for maximizing the time that can be productively used in the test field. Online calculations with appropriate monitoring algorithms and automatically executed post-test analyses make it possible to detect errors and deviations at an early stage, to consequently prompt time-efficient cancellation of the test and to repeat it immediately while the device under test (short: DUT) is still available in the current configuration. The capability of WTCS to use multiple operator stations simultaneously in different roles provides the test bed operator and the test engineer with the possibility of direct cooperation. To make the best use of measurement time, the engineer can evaluate the data of the previous test, monitor the current live data of the test in progress and prepare the next test while the test bed operator is still performing the current test.

QUALITY

Owing to the comprehensive automation of tasks, WTCS as test automation reduces manual errors significantly. With suitable interfaces, test bed automations based on WTCS can be integrated into the corporate processes of test and development departments to enable data flows without media breaks. The system's powerful local test management, which summarizes all information on a test and can document all changes and work steps, contributes to achieving compliance with necessary workflows. This way, WTCS supports standard-compliant work, e.g. according to ISO 17025 or for tests according to measurement procedures such as WLTP.

COST REDUCTION

Standardization in the test field by means of the WTCS platform significantly reduces the development effort for automation and integration of the different test beds. Using the hardware abstraction layer (HAL) also makes it easy to exchange subsystems without changing other subsystems, methods or basic system properties. The broad user base of WTCS encourages the continuous development of basic components and new software modules are created using real-life use cases as starting point. All users can license these new components and, thus, benefit from new software modules.

STABILITY

Being a platform that has been tried and tested in many years of practical use, WTCS offers a high level of practical relevance and a very low error rate. The use in many installations in a broad range of applications caters for a high test coverage in development.

FUNCTIONS

WTCS provides all the functions required for the smooth and efficient operation of compact component test stands, large test beds and test field monitoring systems.

Subsystem integration

WTCS seamlessly integrates all subsystems of the test bed via interface drivers. The drivers serve as a hardware abstraction layer (HAL) that isolates the individual subsystems and enables an easy exchange of the individual subsystems over the test bed's entire life cycle. That means, the subsystems are kept independent of each other, which facilitates the commissioning of the subsystems as they can individually be tested and integrated into the system. In the event that one of the subsystems fails, the rest of the test bed remains operational.

The communication protocols of the individual subsystems vary widely. Here, WTCS is the mediator between the worlds: both established industry standards such as ProfiNET and MODBUS and proprietary protocols based on TCP/IP, for example, are supported or can be integrated individually.

By integrating the subsystems that control the test bed as well as the measurement systems for data acquisition, WTCS acts as the central instance that combines, monitors and controls all data and processes on the test bed.

Manual control

The user interface of WTCS provides the user with access to all subsystems and measurement systems. Each parameter can be influenced manually. To ensure safe operation, input limits can be taken into account depending on the test bed's operating states. Thus, the user at all times has full control over the entire test bed in one central system.

Automatic test sequences

WTCS provides different test sequencers for automatic sequences that are tailored to the respective use cases. Just like users with manual control, the test sequencers too can access all parameters. A combination of automated sequences and manual control is also possible. This means, for example, that the test sequences can be stopped in the event of an error in order to make manual corrections and to resume the sequence again afterwards. Manual fine adjustments in automated sequences are also possible. Both manual and automatic specifications are recorded together to ensure full documentation of the actual test execution status at all times.

The powerful options of the test sequencer of WTCS also allow parallel processes that can be merged again based on synchronization points – thereby allowing for the mapping of concurrencies. In the background, sequence- and DUT-dependent monitoring operations can be performed, for example to influence or abort sequences.

Moreover, the development of test sequences as well-defined, fixed test methods by test field engineers suits to increase quality. The test bed operators just select the ready-made methods in order to parameterize them. This way of working increases efficiency as the susceptibility to errors is low and the work progress on the test bed is faster.

Test management

WTCS offers an integrated test management for local tasks at the test bed as well as interfaces that ensure connection with higher-level test planning and data management tools. So, WTCS can easily be integrated into higher-level company processes. WTCS works perfectly with Werum's own test planning and process management system HyperTest. Using the existing interfaces, though, it can just the same be connected to other existing process management systems without any problem.

The WTCS Test Management module offers the complete description of tests including all metadata about the test, the device under test (short: DUT), the equipment used and other information that can be configured specifically for the application. A test project is logically divided into test sessions, which correspond to the period of time a DUT has on the test bed, and test runs, which describe the execution of a specific test procedure. In test runs, test steps can be used as sub-units for quasi-static measurements or profile repetitions in order to structure the data acquisition even more detailed.

The test management is a fully integrated database-based solution that provides templates for the efficient reuse of information and comprehensive research options for users. Comprehensive documentation of test execution and a complete change history make it possible to comply with important quality standards like ISO 17025 and to work in line with measurement regulations like WLTP.

WTCS supports simultaneous operation from several workstations. This allows close cooperation between test bed operators and development engineers in large test beds to achieve an efficient use of the available test bed time and an optimal provision of data to different user groups. For better user support, the presentation of information can be tailored to the individual user roles.

Data management

WTCS provides internal directory structures for data recording which correspond to the test organization structure of the test management. On the one hand, the data accruing in the test bed automation is recorded and, on the other hand, the data recorded locally by the measurement systems is automatically fetched from the measurement systems. To enable the measurement systems to adequately maintain the data, WTCS also makes the metadata of the test management available to all subsystems via corresponding interface drivers. The directory structures for data acquisition and storage can be structured in more detail by means of configuration, e.g. according to measurement data, evaluations, reports, photos etc.

The roles and rights system of WTCS manages the access to directories and files and ensures that only authorized users can view the data on the test bed. This also allows operation by different internal and external customers without data of the different user groups becoming visible to unauthorized persons. At the same time, users always have full access to the data of the current test. To ensure smooth customer operation on the test bed, access is provided in the simplest form via constant network shares. To increase efficiency and quality, WTCS supports automatic background processes for archiving and hard-disk cleanup, which relieve operating personnel of time-consuming routine tasks and avoid manual errors.

Evaluation and reporting

WTSC provides for seamless integration of evaluation tools into the work process. Standard tools like NI DIAdem™ are automated by WTCS in such a way that "post-test" evaluations and report generation can be performed entirely without manual intervention directly after the measurement data were acquired. Comprehensive basic scripts for file handling and data processing can be used to create individual evaluations efficiently and in no time. The test management starts the analyses directly at the end of test steps, test runs or test sessions. The metadata from the test management can also be included in the analyses. So it is possible, for example, to select the report language or to determine the range of evaluation steps depending on the test type.

In the evaluations, data can be normalized, merged or evaluated according to standard criteria, for example. PDF reports can be generated as part of the evaluation, which can be used as test certificates in the gapless documentation, e.g. according to ISO 17025 or for DUT homologations. If test certificates and documentation are kept in a higher-level system like HyperTest Boost, for example, or another test process management system, data and reports can be transferred to this system using the available interfaces of WTCS.

Integration into corporate processes

WTCS can be fully integrated into the corporate testing process. The automatic transfer of test orders from test management systems, e.g. from HyperTest Boost or any other test process management system, avoids manual transfer errors and takes tedious routine work off the users' shoulders. The bidirectional exchange of master data like persons, DUTs, test sequences or analysis procedures minimizes the maintenance effort and increases data consistency.

Connecting further systems like archive systems or data management systems guarantees a fully automated, error-free and seamless transfer of result data to corporate systems. All meta information of the test together with change history, comments, measurement data, evaluations, reports and any accompanying documents like photos, for example, are treated as one structured and comprehensive data set in order to ensure data consistency and quality.

Additional functions

WTCS offers a variety of practice-oriented standard functions for test configuration and execution. Interface processes can be used not only to integrate subsystems within the test bed. The WCTS can also be connected to company-wide test management and data management solutions. In addition, the WTCS modules offer standard components to look after any aspects of manual and automated test bed control. Very specific use cases can be covered by implementing further additional components. For this purpose, programming interfaces (APIs) to all important core functions are available in common programming languages.

Configuration and administration

For use in a wide range of test beds and test fields, WTCS offers a high degree of customization options. In addition to the selection of the modules as the first individualization step, the modules themselves are also largely configurable. Users can further configure the modules in convenient administration dialogs and thus adapt them without spending a great deal of time and money.

Comprehensive automatic processes, such as data archiving, hard-disk cleanup and system monitoring, are largely automated and minimize administrative work. For the rest of the manual tasks, administrators are provided with convenient administration dialogs to complete the tasks as efficiently, intuitively and accurate as possible. As a result, WTCS-based automation systems can be supported directly by the specialist departments in many test areas without the need for service agreements with central IT departments. This ensures short decision-making paths and fast response times. A maintenance and support contract ensures availability and continuous further development.

MODULES

WTCS has a modular structure and offers a base package that can be extended by adding optional modules:

Base package

Data Server

The WTCS Data Server is used for central data distribution. The Data Server's main component is the Value Pool, in which the current values for all parameters of the test bed are provided. All authorized processes can read these values or write new values for the configured parameters into the Value Pool. The connected Security Server manages the access authorizations. The integrated Data Logger stores all values in a ring buffer database in chronological order and independent of test execution. They can be used for analysis purposes. The WTCS Data Server also includes a calculation engine that enables the parameter values in the Value Pool to be converted into new values. Formulas and conditions can be used in these calculations. So, new values can be derived from measured values, for example, raw measured values can be offset against a calibration value or complex state changes in the system can be visualized for the user in a simple and understandable fashion.

Data Exporter

The WTCS Data Exporter serves the purpose of test-related data recording. It is commanded by the Test Sequencer and performs the recording of parameter values during a test sequence or a test step. Different parameter sets for different tests can be recorded via so-called export lists. Several export lists can be used simultaneously as an export configuration.

Data is recorded in files. The directories are provided by the WTCS Test Management on the WTCS Server. Different file formats are available for data recording purposes: in addition to text-based formats like CSV, recordings can also be made in binary formats like TDMS.

Order Loader

The WTCS Order Loader represents the interface between the test bed and the corporate test planning and test process management. It can retrieve test orders for the test bed from a test process management system and transfer them to the WTCS Test Management for further processing and execution.

In order to align master data, the WTCS Order Loader can exchange lists of DUTs, components, test sequences, analysis methods etc. with the global test management.

Both a file-based method as well as a web service provided by the global test management can be used for transmission where an XML structure is used as data format.

Werum's test process management system HyperTest Boost already comes with the appropriate interface for data exchange, but data exchange with third-party systems is no problem either since Werum offers the HyperTest Test Bed Adapter as universal software solution to connect test beds to the testing process.

Archiver

The WTCS Archiver acts as interface between the test bed and an archiving system or a data management solution. It cyclically queries the completed tests from WTCS Test Management and packs the data of the tests found into archive packages that can be transferred to the archive or data management system together with a description file containing all the tests' metadata.

The transfer is done file-based via drives for file exchange. On successful transfer of the data to be archived, the WTCS Archiver also carries out the secure deletion of result data from the WTCS Server as soon as the configurable retention time for the data has expired.

Event Management

The WTCS Event Management performs the continuous monitoring of parameters in the Value Pool. If limit violations occur, for example, they are visualized in the user interface. It is also possible to have actions triggered by specific events that can be defined by rules. Such an action can be the sending of an e-mail at certain hard disk fill levels, but it can also be the abortion of test sequences in certain operating situations. In addition, all error messages from subsystems and WTCS processes are collected on the WTCS Server via event management and visualized for the user in the interface. Another task of the WTCS Event Management is to collect all error messages of subsystems and WTCS processes and to visualize them for the user in the interface.

Graphical User Interface

The WTCS User Interface is a framework that provides windows and displays for standard views, supplemented by the administration dialogs and the displays of the other WTCS modules. In addition, individual, application-specific displays can be implemented to make sure the operator is provided with the optimal presentation of test bed information.

Display configurations once set up by the user can be saved as so-called workspaces to be recalled when needed. It is also possible to define a default workspace the application is started with, e.g. to welcome every user with a well-defined and familiar overview when starting the application

Analysis Framework

The WTCS Analysis Framework controls analysis programs, such as NI DIAdem™, and also provides corresponding libraries with basic scripts for NI DIAdem™.  The Analysis Framework is controlled by the WTCS Test Management and can subject the available data to an individual data analysis at the end of a test session, test run or test step. The analyses can be used for the purposes of data normalization, checks for conformity to standards, calculations of result data or the creation of test reports.

Optional modules

Subsystem drivers

The modular, configurable subsystem drivers seamlessly integrate the subsystems and measurement systems of the test bed into the automation system. They form the hardware abstraction layer to decouple the individual subsystems from each other. To facilitate commissioning, the drivers are stand-alone-capable having their own interfaces and can therefore be used for interface tests in early setup phases.

The drivers are configured to communicate with the respective subsystem. For this purpose, the communication protocol is selected from the existing interface plug-ins or a specific plug-in for special protocols is implemented. Furthermore, the data to be exchanged between the subsystem and the driver are configured.

Test Management

WTCS Test Management organizes the meta information on test orders, DUTs and any other test-related circumstances. In addition to pure metadata, documents and images can be stored to enable comprehensive documentation of the tests. The test management serves to ensure efficient use of the test bed and quality assurance purposes by documenting the execution. In addition to the actual database-based test management, this module also includes administration components. They create the necessary directory structures on the WTCS Server for the measurement data and accompanying documents during the processing of the tests, provide network shares for direct data access to the current test or retrieve result data files from subsystems. Likewise, the test management and the Test Sequencer together control the data recording by commanding the Data Exporter.

Test sequencers

Two test sequencers are available for WTCS, which are ready to be used in a wide range of applications.

The WTCS "Basic" Test Sequencer allows the compilation of sequential runs from a fixed set of basic steps in the WTCS user interface and the simple and intuitive execution of these sequences. If there are only simple requirements on test sequences, the Basic Test Sequencer is the right choice.

The WTCS "Advanced" Test Sequencer, by contrast, suits to cover rather complex requirements. It consists of a server-sided execution component and a user interface for configuration and execution. Using NI TestStand™ as test execution engine, extremely complex sequences can be created. For this purpose, experienced users develop short sequences – so-called methods – in NI TestStand™. The test bed operator assembles the methods and parameterizes them in a configuration view of the WTCS user interface. Sequences can be nested or repetitive procedures can be configured. This is a process-safe, convenient and efficient way to create highly complex test sequences.