With the advent of the Internet of Things (IoT), industries around the world are undergoing a major digital transformation. In their 2017 research, Capgemini reported that smart factories could contribute an annual added value of $500 billion to the world economy in the next five years. They also found that overall productivity is expected to increase by at least 27% each year, and smart factories could account for up to 60% of all manufacturing plants by 2022.

As optimistic as it sounds, the realization of smart factory initiatives is inherently challenging. One of the first and biggest hurdles is found right where IoT starts – gathering operational data at the edge and communicating it to the cloud.

Most legacy assets, machines, and facilities across industries were not designed to connect beyond plant networks, creating huge data silos within the factory. This leaves companies with two choices: building entirely new, greenfield plants with native IoT technologies or updating brownfield facilities for IoT connectivity.

The first approach is very cost-prohibitive. Typically in auto manufacturing, a greenfield smart factory setup is estimated to cost from $1 billion to $1.3 billion – around 200 times as much as a brownfield. Besides, as industrial systems are very capital intensive and often have a long lifespan of several decades, completely replacing them is not a choice for most manufacturers.

So how can you transform brownfield plants into digital factories of the future? Below we explain three practical ways to IoT enable your legacy systems and harvesting multi-level operational data – from machinery and process data to environmental data.

1. Retrofit Assets and Equipment with IoT Sensors

With a drastic drop in sensor prices in the last few years, outfitting existing infrastructure with new IoT sensors is probably the most cost-effective way to aggregate a wide array of data on the shop floor. In this context, an IoT gateway – capable of collecting data from field sensors and communicating them to the cloud using standard application protocols like MQTT – is often required.

Isolated, “stand-alone” industrial assets (e.g. tanks, pipelines, valves, etc.) – with little or no prior sensing and communication capabilities – can now be retrofitted with smart sensors to become IoT-ready. IoT sensor networks can also be deployed to monitor and control facility-wide environmental factors that influence various production processes and product lifecycle. The emerging Low Power Wide Area Networks (LPWAN) have garnered growing industrial interest for its ability to affordably and power-efficiently connect massive IoT sensors, over long distances and in physically hindering conditions.

Alongside built-in connectivity, many current IoT sensors offer multiple sensing capabilities – from temperature, humidity and pressure sensor to gyroscope, accelerometer, and magnetometer – in a single device. A typical example is micro-electro-mechanical sensors (MEMS) introducing smaller size, less power consumption, and higher accuracy. These sensors offer a convenient, plug-and-play solution to acquire a multitude of operations parameters with a minimum hardware requirement.

2. Enable Existing PLCs with IoT Connectivity

Even before the emergence of IoT, sensors, and actuators had already been widely adopted for real-time automation and controls of many industrial machines and processes. These automation systems – managed and supervised by Programmable Logic Controllers (PLCs) – generate vast amounts of production data that can be analyzed to derive actionable insights.

Today, most brownfield PLCs and associated sensors operate in a local, closed-loop environment – without any capability to exchange data with the outside world. Since all process information is concentrated in the PLCs, getting them connected to the Internet would be a major leap in integrating existing operations systems into the Industrial IoT (IIoT).

While modern PLCs often come with an Ethernet interface, most, if not all older or less expensive PLCs adopt an almost bewildering range of serial communication and proprietary protocols. Any redesigns or modifications of PLCs to integrate add-on IoT connectivity or relevant interfaces are seemingly unfeasible due to the extreme complexity and potentially long production downtime.

Instead, a converter – that can both interact with and extract sensor data from PLCs using automation-specific protocols, and communicate these data to the external world leveraging wireless IoT connectivity – could be employed. Such a converter acts as an IoT edge node capable of data communication to the cloud through an IoT gateway. This approach is particularly handy for remote PLCs with wiring constraints – involving minor changes and almost no interruption in functioning systems.

Of course, you always have the choice to completely substitute older PLCs with state-of-the-art, cloud-capable devices newly offered by major vendors like Siemens, Schneider, and WAGO. But the substantial investment and associated downtime can’t be underestimated

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3. Substitute Remote I/O Units with IoT-Connected Ones

Another way to IoT enable legacy systems without sophisticated and expensive PLC-reprogramming is to replace I/O modules with IoT-ready ones. I/O units are not necessarily embedded in a PLC and can be located farther away – in which case, they are referred to as Remote or Distributed I/O. Today, there are more and more possibilities to retrofit new, remote wireless I/O units in brownfield controls systems.

For example, TE Connectivity and SAP are jointly working to deliver an I/O device which has intrinsic cloud connectivity while being able to re-use existing physical connectivity to communicate with the legacy PLC and sensor. It can extract relevant sensor data and transfer them directly to the IT system. Likewise, Advantech has introduced the new WISE-4000 family with WLAN capability to their remote I/O product category. With continuous advancements in IoT communication technologies, future generations of wireless I/O devices are expected to constantly evolve – offering other innovative connectivity solutions.

Upgrading brownfield plants is a practical entry point on the path to digital transformation. Whether you choose a single approach or a combination of these three approaches, it all comes down to a reliable, cost-effective and least complex retrofit solution.