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Finding Your Way Through the ASAM Data Network

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The following document describes the ASAM ODS model and the data format ATF/XML. You can use this model in DIAdem to generate different perspectives of the data which provides engineers with individual views of relevant data.

An example demonstrates the flexibility of data that you store with ASAM ODS. The document explains the underlying data model and presents possible adjustments.
 

ASAM ODS

ASAM ODS is an object-oriented Base model defined by ASAM e.V.. The isolation of fundamental elements of a measurement and automation environment guarantees a standardized interpretation of data from various application areas. The methods and rules defined in the model enable the user to customize the base model.
Standardized exchange formats and interfaces facilitate the exchange of data between the ASAM ODS compatible platforms via relational data bases or via the XML-based file format ATF/XML.
 

ATF/XML

The following example uses the standardized ISO format ATF/XML for saving data. This format is XML based and contains a model that uses components from the ASAM ODS base model kit. The ATF/XML file describes a so-called application model that customizes the base model. The data is then saved in the file according to the defined model.

Data Model

The following Graphic displays the data model that is described in the example. This data model uses ASAM ODS base model elements that offer a universal structure for data in the field of measurement and automation technology.
Each box in the graphic represents a used element. Every box contains the name of the element. The black lines stand for the connections between the individual elements. The graphic displays in brackets the class of the ASAM ODS base model which the element derives from. You can select any name for the elements when you create the application model and so customize the names. The example uses an environment for data from engine tests.

applied model

Description of the Used Elements

  • TestBed (AoTest): The AoTest type node is the first element of the main ASAM hierarchy that is identified by a green background. In this example, instances of this type are called TestBed and describe various test stands. A relational attribute connects these elements with the Tests of a test stand.
  • Test (AoSubtest): Elements of this type identify tests that were carried out at a specific test stand. The following relational attributes connect these elements with associated elements:
    • A Test includes various measurements: Measurements
    • The Test was carried out at test stand TestBed 
    • The test engineer who performed the test: TestEngineer
    • The unit under test (UUT) on which the test was carried out: Engine
  • User(AoUser): These elements of the data model show the engineers. The example has test engineers and design engineers. The following connections are possible for the User instances:
    • The tests of a test engineer: Tests
    • The engines of a design engineer: Engines
  • Engine (AoUnitUnderTest): Instances of this class are various engines on which tests were performed. There are connections to
    • The design engineer who developed the engine: DesignEngineer
    • The Tests that were performed on this engine
  • Measurement (AoMeasurement): Elements of this type contain the various measurements that belong to the individual Tests. A measurement corresponds to a channel group (ChannelGroup) known from a TDM data model.
  • MeaQuantity (AoMeasurementQuantity): Instances of this class contain the measurement values of a measurement, for example, velocity, pressure, or temperature. Here, bulk data can find its way into the data model either directly in the ATF/XML file or separately in a binary file. There are connections to
    • The related measurement: Measurement
    • The unit the measurement value has: Unit
A measurement value corresponds to a channel (Channel) known from a TDM data model.
  • Unit (AoUnit): This element specifies the physical unit of the measurement values, for example, g, kg, mg, or lbs. The Unit comprises the physical unit of the SI system, a scaling factor, and an offset.


Individual Perspectives of the Data

A great advantage of storing data in compliance with the ASAM ODS standard is the flexibility. In a typical environment in which data is created, different persons view data from different perspectives. In the example environment you can see that the design engineer starts analyzing the data at a different point than the test engineer.

Perspective of the design engineer

Perspective of the design engineer                    


Use Case: Danny Designer received feedback that a diesel engine he developed causes problems on long trips. Therefore he wants to analyze the results of the previous engine tests. He is especially interested in the endurance tests.
He requests all tests executed on the respective diesel engine. Then he selects the endurance tests and loads the related data into DIAdem.

Perspective of the test engineer

Test engineer view      TestIngs View



Use Case: In order to improve his test procedure Tim Tester wants to list all the endurance tests he ran. First he requests all tests he ran. Then he selects some tests from the list and analyses his test procedure on the basis of the measurements.

Tested engines

enginesTestIngView


Use Case: A product manager wants to gain an overview of whether the test procedure that a new engine completed was extensive enough. He starts his search at the individual engines, selects an engine, and analyses the individual tests of the engine.

Used test stands:

Testbeds   TestBed View

Use Case: A plant manager wants to gain an overview of which tests were carried out on a specific test stand in his factory. He selects the test stand he wants from the list of test stands and analyses the tests that run on this test stand.

Extending and customizing the data model

Customization


The following example refers to tests in the area of engine development. However, you can easily make slight changes and adjustments to customize the data model in order to use it for other application cases.

For example, you can assign the name of the objects to be tested such as car, washing machine, processor, or solar cell to the AoUnitUnderTest type element. In this example it is Engine. You can map the individual details of the application environment on the data model. You also can modify or add attributes of the individual elements. The above Figure shows a possible customization of the elements User and Engine.


Example

The core of the example is the ATF/XML based file database.atfx that contains the ASAM data model. Because the necessary DIAdem commands do not differ, you also could use an ASAM database instead. The file contains a relatively large number of instances of the different elements (TestBed(44), Test(347), Measurement(1181), MeaQuantity(5905), User(87), Engine(172), Unit(32)).

The various instances constitute a complex network in which you cannot simply navigate on the basis of a simple tree structure as is used in many file browsers. In this case the ASAM data model can assist. As the following example demonstrates, the definition of different perspectives enables the individual user to customize the navigation.

Starting the example

Complete the following steps to start the example:

  1. Download the packed file.
  2. Unpack this file.
  3. Load the Example.vbs file into DIAdem SCRIPT.
  4. Click Run Script to start the file. The script opens the browser window displayed below with the data from the database.atfx file.

The following figure shows the main window of the example which illustrates the flexibility of ASAM ODS. Use the list with the green frame to switch between the various views of the generated data. Depending on which data is selected, the browser in the lower area of the display shows other start elements:

  • Testbeds: Start at the test stands
  • Test Engineers:  Start at the test engineers
  • Engines: Start at the different engines
  • Design Engineers: Start at the design engineers
  • Create_Measurement: Shows the standard view of the ASAM data service. In this setting you can browse through the main ASAM hierarchy.

[+] Enlarge Image



You can limit the selection of the respective start objects with predefined filters. For example, you can show only the test engineers who work in Block D and who made type C tests. This means you can search for data according to special characteristics and load the data into DIAdem in order to further analyze this data.


[+] Enlarge Image


Refer to the DIAdem help for further information on ASAM ODS commands, the used browser OCX, and the ASAM data service.

References

         

Downloads

explasamdatanet.zip

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This tutorial (this "tutorial") was developed by National Instruments ("NI"). Although technical support of this tutorial may be made available by National Instruments, the content in this tutorial may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this content with each new revision of related products and drivers. THIS TUTORIAL IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).