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How to connect legacy factory automation systems to Industry 4.0 without disruption

Factories are transforming as Industry 4.0 and the Industrial Internet of Things (IIoT) gains momentum. Among other large-scale automation functions, Industry 4.0 brings widespread machine-to-machine communication (M2M) to the shop floor. This creates the opportunity for more data gathering and analysis to increase productivity and improve efficiency.

While M2M has been accelerating in recent years, it is not new, having been a part of the digitalization of the factory stretching back decades. Modern wired and wireless M2M technology, such as Industrial Ethernet and Wi-Fi, are streamlined and efficient, but this long history means there are many legacy networks in place. Such networks use older technologies such as programmable logic controllers (PLCs), which transfer data over wired networks employing serial data technologies such as RS-232 and RS-485. This presents factory managers with a dilemma. Retaining older communication systems means missing out on the productivity benefits brought by Industry 4.0, but upgrading the factory to bring in Industrial Ethernet is expensive and disruptive. Worse, many older

machines are typically controlled by a generation of PLCs that are not compatible with newer Industrial Ethernet protocols such as Ethernet/IP and ModbusTCP. Yet those machines could have many years of useful life left. An industrial gateway can provide a cost-effective interim solution by bridging between legacy infrastructure and an Ethernet backbone as it is phased in. This article briefly describes the benefits of an Industrial Ethernet network and modern industrial protocols for improving factory productivity and efficiency. It then addresses how an industrial gateway can provide a quick and easy solution for bridging legacy infrastructure and the Ethernet backbone. The article will introduce two industrial gateway examples from Weidmüller and describe how to use them to link a PLC running an RS-232/RS-485 serial data technology to an Ethernet/IP backbone. A short history of industrial automation The digitalization of factories really got started with the invention of the PLC in 1969. A PLC is a specialized type of computer that continuously runs a single program. A key advantage of a PLC is its virtually real-time and highly repeatable program execution. They are also relatively inexpensive, reliable, and robust. A good example is

Written by: Steven Keeping, Contributing Editor, DigiKey

Figure 1: PLCs are the mainstay of factory automation and are inexpensive, reliable, and robust. Image source: Siemens

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