Is MQTT Winning the Industrial IoT Race?

Beyond OPC UA’s solid stance as the most widely recognized and used protocol standard to connect industrial devices of all flavors to the edge or cloud for Industrial Internet of Things (IIoT) applications, there are number of other protocols vying for wider use in the industrial space. These protocols include MQTT, AMQP and CoAP, among others.

While attending the Ignition Community Conference (ICC)—Inductive Automation’s annual user event—more than one person indicated to me that they believe MQTT is winning this race. Hearing such comments at ICC is not entirely surprising considering that Inductive Automation is closely partnered with Cirrus Link Solutions, the president of which, Arlen Nipper, is one of the co-inventors of the MQTT protocol.

Read more about Arlen Nipper and MQTT.

But I regularly hear a great deal of support for MQTT from a variety of automation technology companies—ranging from large hardware and software concerns, such as Schneider Electric, to suppliers specifically focused on data collection and transmission, such as Moxa.

由归纳自动化销售工程联合主管Travis Cox提供的ICC演示中强调了MQTT在IIT领域上升的关键方面。这些方面包括MQTT：

• 访问控制列表 - 控制谁可以访问MQTT主题，并且允许哪些操作在MQTT服务器中定义；
• 有效载荷 - MQTT消息的实际内容可以是XML，JSON，文本，图像等，这使其非常适合各种工业应用；
• Stateful awareness—this is a critical factor in the industrial control space. MQTT issues birth and death certificates upon new client connections on the network and when connections are lost, respectively;
• Publishing process/bandwidth use—upon connection, MQTT initially publishes everything about the connected device to the MQTT broker. After that initial burst of data, MQTT only publishes information as data from that device changes. This is key to the low network bandwidth requirements of MQTT, in addition to its small seven-byte header.

处理数据
The Big Data access so key to any IIoT application means that industry must connect devices to infrastructure, not connect devices directly to apps, said Nipper in his presentation at the ICC. This move is often referred to as decoupling devices from applications. “IT made this move years ago with software oriented architectures; now industry is doing it with MQTT,” he said.

Read more about this concept of decoupling devices from applications.

这种解耦方法提供的关键优势包括“有效的带宽利用率 - 您可以在同一带宽上发送更多数据；为标签和相关项目启用真理的单一来源 - 在使用MQTT点火之前，将花费一半的项目成本查找和重命名查找标签；提供插件功能；并消除了SCADA系统的剪裁。” Nipper说。“ 20年来，Phillips 66一直在使用MQTT并行运行旧系统和新系统，这使他们一次可以在一个系统上变色，因为新系统得到验证可以正确执行。”

Explaining that the evolution of IIOT will not be a downward move from IT to OT, Nipper said the move will be more about “empowering OT with tools to execute an OT to IT migration. Ignition is one of those tools because it’s more than HMI/SCADA—it’s an MQTT to OPC UA bridge; it’s an OT to IT bridge that, in addition to HMI/SCADA, also includes MES and OEE as well as edge and cloud connectivity.”

到达这件事
Also speaking at ICC, and further highlighting the advances Inductive Automation and MQTT are making in the industrial space, was Kenny Heidel of Magnetrol, a supplier of industrial flow and level measurement and control technologies. Heidel noted that Magnetrol relies heavily on use of the HART protocol in its SmartLevel transmitters. The HART protocol enables Magnetrol transmitters to contain advanced diagnostic information as well as software to help the device troubleshoot itself. Despite all these capabilities, Heidel said that, in most applications, users typically only implement one variable for transmission via HART—the current output, “leaving all the rest of the information on the device.”

Given this reality, Magnetrol, as an OEM, wanted a way to trend all the data in its transmitters via an easily accessible infrastructure to help the company transform its reactive service model to a proactive one. Heidel said the goal for Magnetrol is to continuously monitor and improve measurements in real time for its customers 24 hours a day. To do this, Magnetrol realized it would need an edge-of-network device that could communicate with its devices and convert the resulting information into MQTT messages that could be published over any available network connection.

This led to the company’s development of its BlueTech gateway. The gateway uses Inductive Automation’s Ignition with MQTT to monitor process conditions continuously in real time and provide historical trends for up 350 tags per Magnetrol device. It also supports up to six dashboard screens per device to relay all of the data and analysis it provides.

The gateway is able to deliver all of this data by “converting transmitter information into MQTT Sparkplug tags that are immediately discoverable by the Cirrus Link MQTT Engine Modules for Ignition as native Ignition tags,” said Heidel.

Read more about how Sparkplug works.

As an OEM, BlueTech gives us the “big picture of what’s happening in the application,” said Heidel. He added that the cloud-based BlueTech gateway is secure because the data flow with MQTT is only outbound; plus, the technology uses a GRE encrypted tunnel to the cloud and firewalls for connections to mobile and desktop devices.

“Level output plays heavily into the efficiency of our customers’ processes,” said Heidel. To correct any output errors requires knowing when it's a problem with the transmitter or the setup. “Using Ignition and MQTT helps us identify and correct these issues. And the 24/7 data logging has allowed us to move from being reactive to proactive” as an OEM to help our customers.

海德尔强调了Magnortol已开始使用其Bluetech仪表板的各个行业的几个客户。这些公司包括：

• 食品成分制造商，其块状固体垃圾箱有问题。该垃圾箱会无意中引起人们对水平发射器的准确性失去信心。“通过Bluetech网关监视垃圾箱，我们能够识别设备中引起错误错误的特定设置。现在，制造商几乎收到零错误警报。”海德尔说。
• 一家钢铁公司，配备了被动磁铁技术，用于水平监测经历的问题，这是由于不可避免地收集了淬火坑中的碎屑。Heidel说，安装“使用Bluetech的非接触式雷达级发射器使我们能够从设备中获得连续的输出，并对碎屑进行调整，以便发射器可以忽略它并提供精确的水平测量。”
• A chemical processing customer of Magnetrol’s uses tall, narrow vessels to contain a number of various chemicals. These chemicals have varying dielectrics which affect level transmitter performance. “With BlueTech, we’re able to determine the correct setup of the level transmitters in these vessels for each different batch, so that the processes can be more efficiently run with accurate level readings,” he said.
• 磁放大器的一个电力生产customers used a specific gravity-dependent level transmitter to control a high-pressure steam boiler. The company was experiencing accuracy issues with the transmitters, which led the customer to add too much water to the boiler. Heidel said BlueTech was used to confirm the accuracy of a new guided wave radar transmitter through all ranges of the boiler’s operation. This saved the customer a substantial amount of money that it had been spending to treat excess water for its boiler that it did not need to add.