Edge-gateway controllers are crashing the IIoT party. A low-cost PLC that plays well with others, combined with message queuing telemetry transport (MQTT) and a variety of other protocols, could be a big part of the future Industrial Internet of Things (IIoT).
"The big buzz word out there is the IIoT," says Vikram Kumar, CEO at EZAutomation. "Everyone is looking at how they can enhance manufacturing, reduce downtime and improve efficiency and overall productivity. This is causing manufacturers and machine builders to lean toward data collection and real-time data monitoring using cloud-based technology and services along with the MQTT protocol for preventive as well as predictive maintenance."
IIoT is really starting to take off. "It's enabling more preventive maintenance based on dates and usage to avoid breakdowns and predictive maintenance through equipment performance monitoring to anticipate failures," says Kumar. "Data are monitored and high or low values enable notifications via email, text messages or real-time viewing of the data in the cloud via a smartphone."
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Controllers are being used as machine-health monitoring systems. "Users want to monitor machines and preventively take care of problems so they can avoid shutdowns and other maintenance types of issues," says Kumar. "In addition to using their normal controls, they are looking for alternative hardware and software, SCADA packages, health-monitoring PLCs, edge gateways and other edge-of-network types of controllers and devices out there to do predictive maintenance."
It sounds like the industry is moving the direction of PLC-based machine-health monitoring systems, and the use of MQTT protocol may be a popular choice. "There has been much progress in the IIoT world and MQTT protocol," says Kumar. "It's a new thing that plants are exploring. Although there is hesitation, I expect in the next three to five years that every PLC manufacturer is going to be integrating MQTT and IIoT practices. The end users are going to start demanding it."
Specifically, the MQTT protocol is big, continues Kumar. "I was surprised to find that it is the second-most-used protocol in the world behind HTTP," he says. "That technology implementation, putting it into controllers, HMIs and marquees, is a major advancement to take advantage of."
Without changing the existing system, a PLC-based health-monitoring system or data-monitoring MQTT/IIoT can be added to a control architecture cost-effectively. "A system with EtherNet/IP, Modbus and other popular protocols will not just be a PLC, but the new technology makes it an edge-gateway device—a controller with an edge gateway," says Kumar. "Without changing ladder logic in the existing PLC, it can be added to a system and take advantage of the IIoT world while the existing operational technology stays in place."
These controllers can also act as remote I/O devices to an existing controller. It looks like a good new application of technology that is low-cost, is IIoT-ready and provides control. And it's easy to add digital and analog I/O to improve monitoring capabilities. Utilize the gateway I/O, which, as a PLC, is easy to expand; use the existing controller I/O; or use both.
The IIoT will be less dependent on the installed brand of controller. "Rockwell or Siemens controllers may be in use throughout the plant, but adding an edge-gateway controller may be one-fifth the cost," says Kumar. "While a plant may be strict on the brand of PLC used to control machines, it can be flexible on the brand of gateway controller. The choice to use it as a PLC or an edge-gateway controller to the existing PLC technology device opens up many opportunities."
The edge-gateway controllers can use any cloud broker available such as CloudMQTT, Azure and others. These devices are flexible by design, but a supplier could establish its own broker on its own server. To simplify these connections, expect these gateways to have utilities for a dashboard to simplify access to the data. Sophisticated users will create their own custom IIoT dashboards or use HMI/SCADA applications.
"Other than keeping up with the latest processors, as things evolve, other technology we are exploring are wireless and RF communication," says Kumar. "There is much dialog out there about everything from wirelessly powering sensors, PLCs and HMIs to wirelessly communicating between these devices."
Devices are getting smarter. "Not only does the IIoT enable real-time monitoring on smartphones and via emails, but, in plants, everyone has LCDs (liquid-crystal displays), TV screens and marquees showing the production staff useful information," says Kumar. "The technology in the modern HMI, including drivers and connectivity, is moving to message displays and marquees. This will enable programming and monitoring in these smart displays. Technology is pushing PLC and HMI functionality to text displays and it will all be connected to the IIoT."
