Create Asset Hierarchy with emulated data
Understand and build an Asset Hierarchy to define your data collection.
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Understand and build an Asset Hierarchy to define your data collection.
Last updated
Was this helpful?
The Nexus platform makes it possible to create a virtual model of your setup or business that reflects the real world. This model is called an Asset Hierarchy, and consists of the following components:
Areas: Represents static locations or organizational structures. Areas can refer to physical locations (e.g. country, region, site) or organizational units (e.g. teams, business units like sales, marketing, or production). Other meaningful groupings can also be defines as Areas.
Assets: Assets represents entities, such as equipment (e.g. factories, production lines, motors, sensors). Assets can also represent virtual entities, that are not physical, like aggregations (aggregations of values from other assets).
In general, areas represents organizational / geographic structures and assets represent equipment.
It is possible to model everything into one or more separate Asset Hierarchies, depending on your preferences. For example, if you have 10 factories distributed across the world, you could model all 10 factories in the same Asset Hierarchy. However, it is recommended to instead having 10 separate Asset Hierarchies that models each individual factory.
Data Connectors can be defined on an Area. A Data Connection represents a connection to a data source, that can be for example an OpcUA server, Modbus slave or a MQTT broker. The Area where the Data Connector is defined also defines the scope of visibility of the data source. For example, if the Data Collector is created on an FactoryA area, it means that all Assets created in a direct line under the FactoryA Area, are able to use the Data Source.
The Nexus platform has an Emulator Data Connector that is able to provide simulated measurement, without having to connect to external data servers. The Emulator is used for this guide.
Tags are defined on Assets. Tags represents time series data that are either read or written to or from a data source, using a Data Connector. All tags must be assigned to a Data Connector. The tag defines the location to read or write data, and how often it is done. It also defines any aggregation or pre-processing that must be performed.
A tag has both a name and a hierarchical name. The hierarchical name is determined from the location in the Asset Hierarchy where the tag is located. Here is an example:
In the example above, the tag is named "Tag". The tag is located on the "Asset" node, that is a child of the "Area" node. The "Area" node is again a child of the hierarchy root. The hierarchical tag name shows the full path from the root node to the tag. In the above example, the hierarchical name is:
Root.Area.Asset.Tag
The hierarchical name is created by concatenating the Alias properties on all nodes in the path from the root to the tag, separated by a punctuation. Since hierarchical names should be as short as possible, and node names can be very long (and contain special characters), the Alias properties can used to create a shorter identification of a node, to simplify the resulting hierarchy names. All hierarchy nodes have the Alias property, and the Alias default to the node name (without spaces and special characters), but can be changed afterwards. For example, an asset:
By changing the alias for the Asset node, the resulting hierarchical name for the example tag is now:
Root.Area.AS.Tag
The root node Alias can be set with an empty string. This means that the "Root." part of the hierarchical name is removed.
Meta data are collections of key / value properties, that can be assigned to Assets, Areas and Tags. It is also possible to assign Meta Data to the entire Asset Hierarchy. The purpose of Meta Data is to provide context to the data that is collected into the Data Store.
When an Asset Hierarchy is deployed to a device, the entire Asset Hierarchy structure, including the Meta Data, is replicated to the Data Store. When analyzing data in the Data Store, it is possible to access the Meta Data to provide context to ingested measurements.
It is possible to assign Meta Data to the entire Asset Hierarchy, by selecting the root node (the top node). In the "Revisions & Properties" section select the "Properties" tab. Add new Meta Data properties by clicking the "Add property" button.
Meta Data properties can be assigned to Areas, by selecting the appropriate area and editing the properties in the "Area info" section. Relevant properties could be information about the location.
To assign Meta Data to assets, select the appropriate asset in the tree structure, and select the "Asset Info" tab in the "Asset" section. This opens the "Asset info" section where Meta Data can be added. Relevant information could be properties describing the physical equipment.
Finally, is it possible to add Meta Data to individual tags. Select the asset, and select the "Tags" tab in the "Asset" section. In the "Tag" section, select the "Store" tab, where Meta data can be added. Relevant information to add could be unit of measure, status definitions, or other properties that describe the data source, to ensure that it is considered when doing analytics in the Data Store.
In this guide, we will be building a demonstration Asset Hierarchy that uses simulated data. For this guide we define the fictional factory "Odense Factory", that produces plastic items by injection molding. The factory has a single production line, with 3 machines, that we want to monitor.
The structure of the demo Asset Hierarchy should be like this:
The "Printing" node is an Area, that models everything regarding the plastic molding. "Line" is an Asset, that encapsulates all information that relates to the overall production line. The "Machine1", "Machine2" and "Machine3" Asset nodes are child nodes to the "Line" node, and each represent data from individual machines.
Each machine produces data identifying the machine state and production.
The product line produces environmental data, such as temperature and humidity.
In the Nexus Portal, navigate to Assets in the Designer menu. This is where Asset Hierarchies are defined.
Press the "New Hierarchy" button to create the new hierarchy.
Enter a Hierarchy Name in the pop-up, to give the new hierarchy a name. An example is: "Odense Factory".
Enter a description, that describes the scope of the asset hierarchy. An example could be: "This hierarchy represents the Odense Factory plastic molding facility."
Keep the default Data Store, that defines where all measurements will be persisted after data collection.
Click "Create" to create the new Asset Hierarchy.
When the Asset Hierarchy has been successfully created, it will be shown in it's first version, which is version 1. There will be a root node visible, that has the same name as the Asset Hierarchy. This root node is special, and when selected the "Hierarchy Settings" and "Revisions & Properties" windows are shown, which makes it possible to view and set details on hierarchy root level.
Select the root node, and set the Alias property to "OD". This means that the hierarchical name of all tags will be prefixed with "OD.".
Click the three dots at the root node, to get the context menu. In the context menu, select "Add Area" to create an Area node, and name it "Printing". Add Meta Data to the asset node: "vendor = acme".
Create a new Asset node as a child of the newly created "Printing" node, and name it "Line". Add Meta Data to the asset node: "building = a1".
Create 3 new Asset nodes as a children of the newly created "Line" node, and name them "Machine1", "Machine2" and "Machine3".
Save the Asset Hierarchy by clicking the "Save" button, and thereby creating a new version.
To be able to generate data we need a Data Connector to identify the data source. In a real-life setup there would probably be a data server on the factory. Depending on the protocol that the data server provides, an appropriate Data Connected is selected. In this case we use the Emulator, and place it in the "Printing" Area node. Since the "Line" and the 3 "Machine" Asset nodes are children of the "Printing" Area node, they can all get data from the Data Collector.
Select the "Printing" Area node.
Create a new Data Connector by clicking "New data source" button, and select "Tricloud Emulation".
Save the Asset Hierarchy by clicking the "Save" button, and thereby creating a new version.
Select each "Machine" Asset node, and create the following 2 new Analog tags on each node, by clicking the "New tag" button and selecting the analog measurement type. The properties for each tag should be set like this:
Status
Emulator
step;1;15;2;30
Production
Emulator
random;0;100
uom = kg/h
Select the "Line" Asset node, and create 3 new Analog tags by clicking "New tag" button and selecting the analog measurement type. The properties for each tag should be set like this:
Temperature
Emulator
sinus;10;30
uom = deg
Humidity
Emulator
sinus;60;90
uom = %
ProductionSum
Equation
<see image below>
uom = kg/h
The ProductionSum tag uses symbolic equations to create a sum value from the production of the 3 machines. Open the Formula calculator editor by clicking the f(x) symbol:
Enter the tags names of the production values from the 3 machines, and assign each value the symbols a, b and c. Set the symbolic expression to "a+b+c" and click "Add Equation".
Save the Asset Hierarchy by clicking the "Save" button, and thereby creating a new version.
The demo Asset Hierarchy is now ready to be deployed to an Edge Device.
