How Can MQTT Be Integrated With SCADA Systems?

The Industrial Internet of Things (IIoT) has sprouted a whole host of devices that you now need to run a manufacturing plant efficiently. However, many of those devices don’t have enough memory, network bandwidth or processing power to manage the ever-expanding flow of information. Message Queuing Telemetry Transport (MQTT) is a messaging protocol designed to overcome this challenge in industrial automation, facilitating the exchange of data between various necessary applications and devices. This can be of great benefit if you integrate MQTT with Supervisory Control and Data Acquisition (SCADA) systems.  

How Does MQTT work?

The MQTT protocol is designed with a publish/subscribe architecture. This means that it’s built on a messaging pattern where people sending messages (publishers) aren’t directly linked to those who receive them (subscribers). Data exchange between the two is via an intermediary (the broker). The key components of MQTT are as follows:

• Publishers represent a client sending messages, whether that be a person, application or device. They publish these messages to the broker as topics that might interest subscribers.

• Subscribers represent the clients who subscribe to chosen topics on the broker and receive messages related to them.

• The broker is the message exchange intermediary between publishers and subscribers. Topics are managed by the broker so that messages are directed to the right destination.

• A topic represents an information exchange channel to which subscribers and publishers connect. Topics are many and varied, so multiple channels are deployed.

• Quality of Service (QoS) is a way of prioritising message delivery. It offers different levels of assurance for delivering messages, so you can decide how often it happens. Options are once only (QoS2), at least once (QoS1) or once at most (QoS).

• Last Will and Testament (LWT) is a failsafe MQTT setting that kicks in if you go unexpectedly offline. It ensures that the protocol will broadcast a specific message to everyone else in the system.

• Retained messages is a setting that provides the broker with the ability to retain whatever message was last sent on a particular topic.

Using the MQTT protocol to collect data from SCADA is simpler than with traditional industrial protocols. You can also add or remove devices on the system without affecting its overall performance. This architecture’s flexibility and scalability rest on links between publishers and subscribers being unnecessary. 

How Does MQTT Enhance SCADA Systems?

SCADA systems are central to the real-time monitoring and control of automated industrial processes, but lack an efficient and reliable method of data exchange. MQTT can provide this communication channel between industrial devices, enhancing SCADA systems’ capabilities and increasing their power.

Some Advantages Of Integrating MQTT With SCADA systems

1. Reliability and Efficiency 

MQTT is designed to downsize messages, avoiding all unnecessary data for the most efficient transmission. This means you can keep up streamlined communication with even limited technological resources. It also guarantees that critical information is reliably delivered, even in sub-optimal network conditions. 

2. Low Bandwidth

MQTT employs a binary format for messages, so its bandwidth consumption is extremely low. It means that less data has to be transmitted over the network, and it takes less time to communicate between the various users. This helps to reduce latency.

3. Simple to Integrate with IIoT Devices

MQTT is one of many industrial communication protocols. It’s standardised and lightweight, making it easy to integrate with multiple and multi-brand IIoT devices. This makes it highly scalable. With MQTT integrated into your SCADA system, you can vary the number and type of devices in your network almost infinitely without changing its existing infrastructure. 

4. Improved Device Battery Life

This lightweight characteristic of MQTT also means that IIoT devices on your SCADA system consume less energy, so they’re able to operate for longer without having to recharge. This factor alone recommends MQTT for battery-powered devices and sensors.

5. Better Security

MQTT secure protocol is able to carry data in transit with encryption protocols like SSL or TLS. All information travelling between the broker and connected SCADA devices is entirely secure and confidential. If you should chance to lose your connection or experience network instability, MQTT will put the messages into a queue. When a stable connection is reestablished, it ensures they’ll be delivered.

MQTT In SCADA Systems

Many applications integrate MQTT into their SCADA systems for the above-listed advantages. These are some of the most common:

• Integrating IoT and IIoT devices: MQTT is one of the easiest communication protocols to integrate with IoT/IIoT devices. This greatly improves data collection and analysis, and is therefore of great benefit to industrial automation.

• Predictive maintenance: Transmitting data to your SCADA system with MQTT allows for real-time monitoring of your systems and machinery.

• Remote control and monitoring: Integrating MQTT with SCADA systems allows you to manage your operations more easily from any location. Equipment and production processes can be monitored in real time using simple devices.

• Supply chain and logistics: Many industries use MQTT for logistical and supply chain applications where they depend on efficient processing and delivery. Integrated MQTT and SCADA systems in a modern warehouse can enhance communication between different inventory management systems to improve overall logistics.

• Energy management: You can monitor and optimise energy usage using MQTT to collect data from energy meters and transmit it to your SCADA system.

• Environmental monitoring: MQTT is useful for monitoring critical parameters like flow rates and pH levels in industries like wastewater management. This integration helps ensure that your industry is complying with environmental standards.

Key Takeaways On Integrating MQTT With SCADA

Much discussion has led to industry agreement about the advantages of integrating SCADA and the IIoT. At this point, integrating MQTT with SCADA systems is the next logical step in enhancing industrial automation. As we move closer to Industry 5.0, we recognise that benefits like greater security and predictive analytics are more of a bedrock than an optional extra. Such technological advances are essential to make industrial automation ever more agile, smarter and more efficient.