Unified Namespace and Tags

Purpose and Key Concepts

The purpose of the Unified Namespace is to provide a unified and organized data framework.

The key data modeling concepts to organize a Unified Namespace include:

Asset Tree

The Asset Tree is a hierarchical representation of the physical equipment in the production environment. It leverages a group of tags that effectively capture and reflect the real-time state of the equipment. This organized structure enhances data modeling and provides context for tags by establishing a common definition for a set of variables by creating tags based on data templates (UDTs). Additionally, the Assets Tree folders support categorizing and organizing tags and assets within the Unified Namespace, facilitating easier navigation and data comprehension.

Tags

A Tag represents real-time and historical data variables that modules can read, write, and subscribe to.

Tags are Local (created within the solution) or Remote (dynamically accessed via ExternalTags Sources connectivity).

Additional metadata, known as Tag Attributes (e.g., last update time, quality status, description), are automatically generated upon tag creation.

Modules utilize tags in different ways:

1. The Devices module maps tag values to field equipment like PLC registers.

2. The Datasets module links tags to SQL database tables and queries.

3. The Scripts module performs analytics and calculations using tags.

4. The Historian module creates a time-series archive of tag values.

5. The Displays module enables Operator Displays independently show values corresponding to tags, regardless of their data source.

Data Templates (UDT)

Data templates are user-defined data structures known as UDTs (User Data Types). That data structure can include variables of any type and references to other templates, creating a hierarchical data structure. When creating Tags based on Templates, each variable in the template is referred to as a Property. An example of a data template is a simple PID information with the properties ProcessValue, Setpoint, and ControlValue.

Enumerations

Enumerations define a series of potential values or ranges of values for a variable, mapping to messages and colors in each state. When connecting with a Tag, the value of the enumeration enhances data interpretation, providing context to the different states the variable can assume.

External TagProviders

The External TagProviders enable direct interaction with variables in remote systems, bypassing the need to create specific tags in the solution. It establishes connections with tags sources which can be set up in a table or directly in the assets, enhancing the versatility of data access and exploration in the Unified Namespace.

Runtime Database

The runtime database is an in-memory real-time database that stores and manages the Unified Namespace data during the execution of a solution. It provides an event-driven data exchange of the values of tags and assets between various modules, like alarms and displays. The runtime database is implemented by the TServer.exe process, which ensures efficient and reliable data management.

Understanding the Unified Namespace 

Feature Highlights

• Real-time Elements: The system has a built-in real- time, event driven, in-memory database, that manages the tags, assets and events in the application. 

• Real-time Tag Types: A typical HMI-SCADA system has only basic tag types, such as numeric and messages. As the system also targets IT and MES systems, it goes far beyond, supporting real- time entities that match all the SQL types and many .NET Framework entities, including Images and a complete DataTable in a single real-time tag.  

• Dynamic Arrays and References: The system offers built-in support for tri-dimensional dynamic arrays, lists and type-safe reference tags with dynamic assignments, creating reusable components on displays, symbols, reports, calculation and at any part of your solution.  

Purpose and Key Concepts

Unified Namespace Workflow

Woking with the module

The User Interface to build your models can be found Solution Designer tools, under the section Unified Namespace.

From that centralized interface, you can create or import Tag definition, organize the hierarchy and monitor the current values of your variables. 

When you start a new Solution, there already two folders pre-defined in the model.

• The "BaseTags" folder is where all new Tags are created by default.

• The "ExternalTags" folder is where all new External TagProviders connections are added by default. 

The typical process on creating the model is:

1. Creating Data Templates for Assets

2. Creating and Organizing Tags and Folders. Optionally you can use dynamic Tag definition from external data sources using the External TagProviders features. 

Typically the values of Tags will be read from physical Devices, like PLC's or field devices, or used in Displays, Scripts and other modules. But those configurations are executed in each module and not in the data model.

Runtime Execution 

When you start the execution of your solution, the Unified Namespace definition in loaded into a in memory Real-Time Database. The .NET process in the computer implementing that is named TServer.exe

Executable Process, ports, Diagram, data flow

During the execution the Realtime Database, or just called Runtime, provides an event-driven data exchange of the values of Tags and Assets between various modules, like Alarms and Displays.

The chapter Runtime Environment has detailed information on all aspects and process in place when running the solution.

Accessing Assets on Scripts and Expressions

Integration with Other Modules

The various modules of the platform, like Alarms and Displays, can easily access any variable from the Unified Namespace by using its full name or path. 

For example, to access a tag when creating a operator Display, use "Tag." to access the available tags. A tag called Temperature from a data template named Machine 1 would have the full path: Tag.Line.Machine1.Temperature.

The information on the Unified Namespace is also accessible to other application, using the built-in MQTT broker, or its native ability to act as OPC Server. For detailed information, please refer to the corresponding sections within the document and on the pages OPC Server and Client Tools and MQTT Tools.

Third-party applications can also access that data using Integration APIs.

RemoteAssets methods

RemoteAssets methods provide means to interact with assets remotely. They allow you to map and unmap entire assets, and refresh readings of the registered elements. 

RegisterElementToTag: This method allows you to map an entire RemoteAsset to a Tag. It requires that you create a Template with the same structure as your asset. 

@Client.RegisterElementToTag(string assetName, string tagName, [bool readOnly=false]) 

RefreshRemoteTags: Performs a new reading on the registered elements. 

@Client.RefreshRemoteTags() 

UnregisterElementToTag: Removes the RemoteAsset from the registered list. 

@Client.UnregisterElementToTag(string assetName)

UnregisterAllAssets: Removes All RemoteAssets from the registered list. 

@Client.UnregisterAllAssets() 

Troubleshooting and Best Practices

Troubleshooting and Common #Issues

Some common issues that may arise while working with the Unified Namespace include:

#Inconsistency or missing data from external systems:

When using ExternalTags Sources, our software is dependent on the external application to provide and maintain that section of the Unified Namespace, including the variables names and its structure.

Refer the External TagProviders section of the manual on how to diagnose connections with external systems. 

When mapping Tags to Device Communication drivers, the Tag Definition is the Solution, so the Tag name will always show property in the Unified Namespace, but its value in depending on the connection with the remote device.

Refer the Devices, Field Communication section on the documentation for information on setup and diagnose connections with field devices. 

This concept applies to any external data source being used by the system, like remote SQL database or custom scripting using external APIs.

#Inconsistency or missing data after importing:

Ensure that the import files (Excel, CSV, or any other supported format) are properly formatted and follow the guidelines mentioned in the documentation. Check if the required columns are present, and verify that the data types and values are compatible with the destination tables.

#Performance issues

Here are some key areas to review when improving performance: 

#Target Solution

Analyze the structure and organization of your solutions. A well-organized solution with efficiently structured hierarchies can significantly improve system performance. 

#Driver Communication

Use the Monitor Page and Runtime Diagnostics to monitor the communication between the drivers and your solution.  

#Displays

Busy and information overloaded displays can hinder system performance and make the solution more difficult to navigate for the user. Ensure that your screens have only the information they need to operate. 

#Optimization and Grouping

Only use tags that are necessary for your application. Excessive and unnecessary tags can create additional overhead that can hamper performance. Group tags logically based on functionality or the device they are associated with. This not only improves readability but also enhances system efficiency. 

#Reuse Assets

Try to reuse assets where possible. If two components use the same type of asset, consider using one asset and replicating it where needed. 

#Modular Templates

Design your templates to be modular. A modular template can be used in various parts of your solution, reducing the number of unique templates you need to create and manage. 

Best Practices and #Recommendations

To get the most out of the Unified Namespace, follow these best practices:

#Organization of the data structure

• Organize tags into a clear hierarchy, using folders and templates, to make it easier for users to find and understand the information they need.

• Plan your data structure carefully, considering the relationships between assets, tags, and templates.

• Leverage templates to create reusable data structures, reducing redundancy and streamlining data management. Create standard templates for common tasks. This not only saves time but also ensures consistency across your solution. 

• Use ExternalTags Sources to integrate external data sources, ensuring a seamless exchange of information between systems.

• Use a consistent naming convention for your tags. It can make your solution easier to navigate and troubleshoot. 

#Status Monitoring 

• Add to your solution specific Displays and Scripts to regularly monitor and report the system performance, as well as the connection status with the external data sources. 

• Implement alarm conditions when critical connections are lost.

Unified Namespace Runtime Attributes

The Tag has attributes and methods that can be used in .NET scripts, and other system modules. 

This section describes only some commonly used properties.

In this section: