A New Way to Harness IoT Data from Legacy Industrial Systems
If you’re familiar with the manufacturing world, chances are Programmable Logical Controllers (PLCs) are nothing new to you. Having their roots in the automotive industry, PLCs are omnipresent across all modern industries today and akin to the brains of factory automation systems. While coming in many shapes and forms, industrial PLCs are used for a common purpose – real-time production control. A PLC gathers data from thousands of input sensors, processes it and triggers automated actions on the corresponding output device like actuators, alarms and switches.
As the Internet of Things (IoT) disrupts the industrial world, integrating legacy equipment with IoT connectivity becomes paramount. While some might question whether IoT will eventually replace PLC systems, seeing these two as mutually exclusive options isn’t the way to go. Indeed, given massive operational data concentrated in a PLC, being able to interface it with an IoT architecture could unlock unprecedented visibility on the factory floor. Not to mention, PLCs have gained their credit as a robust, versatile automation instrument, and it doesn’t look like manufacturers will move on without them anytime soon.
The Challenge of PLC Communications in Legacy Industrial Systems
Until recently, IoT-enabling PLCs had been a major undertaking. The explanation is simple. Invented in the previous century, they weren’t originally designed to be connected to an external system. PLCs might be able to communicate with each other or to a local dashboard at best, but their core functionality is real-time control, not remote networking. As such, data flows within PLC-managed automation networks are closed-loop and stay locked on the factory floor. On top of that, most, if not all, older PLC models employ a plethora of proprietary, vendor-specific protocols that hamper interoperability and data exchange. As PLCs are intended for several decades of use, it’s not uncommon to find these older models dominating a standard manufacturing facility.
Next-gen PLCs do not come without networking challenges, either. Many of them provide built-in Ethernet capabilities and an onboard web server to be directly plugged into the Internet. Nevertheless, running cables around factories is expensive, dangerous, and conducive to production shutdowns. In many outdoor, geographically dispersed industrial settings with challenging topography (e.g. open-pit mines), Ethernet wiring isn’t even an option. Also, PLC web servers require a case-by-case configuration to enable data sharing with an IoT system.
Despite the common understanding, not all PLCs are integrated into the factory-level Supervisory Control and Data Acquisition (SCADA) system. Doing so often requires complex, error-prone PLC reprogramming alongside cumbersome wiring which cost several weeks of production downtime. Certain SCADA systems are even proprietary and only compatible with PLCs from a specific vendor....
