UNS: Unified Namespace

What Is A UNS And How Does It Work?

7 minute read

Unified Namespace Defined

Digital Transformation is all about data, and companies will only achieve this goal if they manage their data differently than in the past. A Unified Namespace (UNS) is the architectural foundation of successful Digital Transformation initiatives because it enables you to make data accessible from your entire enterprise to a single database. More specifically, a UNS is a standardized way to organize and name data, and it contains an enterprise’s structure and events in one communication interface.

The term “Unified Namespace” was coined by IIoT and Industry 4.0 Solutions Architect Walker Reynolds, who has described it as “a real-time single source of truth for data in an industrial or manufacturing environment, semantically organized like the business and built to be open (not dependent on any one product).”

A UNS combines software and hardware solutions, such as:

A software platform like Ignition to manage the UNS.
An Edge platform like Ignition Edge with software APIs, device, and network connections at the OT level.
Connections to smart sensors, PLCs, and business and enterprise applications.
An MQTT data broker to transfer data between the UNS database and its connections.
A central SQL database or managed cloud data service like Snowflake, SiteWise, or Azure Digital Twins (ADT).

The data from these solutions is organized into an event-driven architecture (EDA), built to capture, process, and respond to events from decoupled systems and publish them in time-series order.

What Are The Benefits Of A UNS?

A UNS improves upon the original ISA 95 industrial architecture, also called the Purdue Model. This architecture uses point-to-point communication: the factory floor communicates with a supervisory control and data acquisition (SCADA) system, SCADA communicates with a manufacturing execution system (MES), MES communicates with an enterprise resource planning (ERP) system, and so on.

With point-to-point communication, each level often uses different data formats, especially if the systems are using proprietary software. This architecture requires specialized software engineering for each layer to communicate, which reduces scalability, stifles innovation, and creates gaps in data. A UNS changes how the different layers of this model communicate with each other by directing data through the UNS instead of layer by layer, leading to many significant benefits.

One of the most important benefits of a Unified Namespace architecture is that it creates a single source of truth with data standardization. It connects all of the data from your PLCs, edge-of-network devices, SCADA, MES, ERP, and more, to one standardized hub with the correct context.

A single source of truth for data reduces the cost and complexity of integrating data at each layer by only using one communication interface and data type for read and write capabilities, like the MQTT messaging protocol. It also increases scalability and traceability, as you can directly integrate data consumers and producers by plugging them into a common network infrastructure. This enables any person, device, or AI or ML model to access data from anywhere in the organization in real time, making it easier to solve problems, do predictive maintenance, get advanced real-time analytics, and streamline communication.

A UNS can also speed up and enable the adoption of Industrial Internet of Things (IIoT) devices and edge systems, leading to faster Digital Transformation. Adopting IIoT-enabled devices is essential for modernizing business operations, integrating modern software and hardware solutions, and enhancing efficiency, data access, and machinery maintenance. Also, IIoT gateways can publish data to the UNS on behalf of legacy devices that are designed for point-to-point communication, allowing you to replace your system at your own pace.

What Is Required For A UNS?

A UNS must seamlessly connect many disparate systems to function correctly in an interconnected data ecosystem. To achieve this, a UNS uses a lightweight messaging protocol, UDTs, data modeling software, and a data broker to transfer contextualized data to the UNS database.

MQTT Enables Interoperability

MQTT is an IT-friendly messaging protocol that enables all of the components in a UNS to communicate from the edge to the cloud. MQTT is the most commonly used publish-and-subscribe protocol for a UNS because it’s reliable, efficient, secure, flexible, open-source, and it decouples devices from applications. MQTT also enables a UNS to communicate wirelessly and bidirectionally, and it's extremely lightweight, which lowers costs and optimizes network bandwidth.

Modeling Data

Data modeling is the process of analyzing and defining different data types from your devices, creating a clear visual representation that explains connections between data points. Without data modeling, data will come from your devices raw and without context.

To create a data model, you can use user-defined types (UDT), also known as complex tags. UDTs allow you to restructure data into a customized and standardized format with reference and derived tags as it’s published to your UNS. UDT instances can inherit definition changes and enable you to create nested directories that can be mapped onto an MQTT topic structure.

The open-source software specification Sparkplug works on top of MQTT and also helps to model data before it reaches the UNS. Architectures with Sparkplug and MQTT are actually the most common for UNS because they solve many common data modeling issues when transferring data from the edge.

Sparkplug defines how MQTT is used by the UNS in a real-time environment, adds metadata about devices, and provides plug-and-play auto discovery. Sparkplug also reports by exception, meaning only relevant values are transmitted to the UNS database, which saves bandwidth, memory, costs, and computing power. Additionally, Sparkplug and MQTT have store-and-forward capabilities, so your data will not be lost if your system gets disconnected.

Transferring Data

After data is produced and modeled, it is sent to an intermediary server like an MQTT broker, which transfers data from nodes to the UNS. The broker first authenticates a device and then authorizes whether it can perform an action by using an access control list that specifies rules for which devices can read or write to which topic in the database.

You might think, “Why not use an MQTT broker as a UNS?” However, this would not be ideal because data brokers are not designed to store data long-term, and it inevitably makes the broker slow and cumbersome.

Databases And Data Cloud Services For A UNS

From the data broker, modeled and contextualized data is sent directly to predetermined topic namespaces within a UNS database or a data cloud service such as Snowflake, SiteWise, or ADT through an IoT bridge. Once the data is stored, you can interface with the database or cloud service through an application like Ignition using SQL queries.

Snowflake is likely the best choice for this because it is specifically designed to be a cloud-based UNS database and it can interface directly with Ignition.

Keeping Your UNS Secure

Cybersecurity is very important for a UNS because IIoT devices are connected to the entire enterprise, making devices easier to hack into compared to multiple point-to-point connections using proprietary systems.

Many manufacturers set up a demilitarized zone (DMZ), or perimeter network, to segment the business network from the plant floor network. A DMZ is often used for IT network security, but it’s also useful for protecting IIoT and OT devices and systems because these can’t be fully protected with a single technology like a firewall. In a manufacturing environment, a DMZ creates a buffer zone between two firewalls (one at your PLCs and one at the Internet connection) where your MQTT broker and its connections to the edge live.

In addition to network segregation, you can set up TLS encryption with MQTT in order to encrypt data in flight throughout the network. However, you will need an SSL certificate from a CA (certificate authority) to enable this capability.

Get Started With Your UNS

Creating a UNS can be a big undertaking, but it is a key step in starting your Digital Transformation journey. Today, integrating your enterprise into a UNS is more important than ever before, as having access to your data becomes increasingly necessary to stay competitive and use modern technologies like AI and ML.

The first step to building your UNS is to download Ignition and check out Cirrus Link Solutions’ modules for connecting to the edge and interfacing with data cloud platforms like Snowflake. For more information, watch our webinar: “Ditch Data Silos: Create a Unified Namespace with Ignition UDTs & MQTT.”