Cloud-based SCADA as an IIoT gateway

Consumer media is awash with articles concerning the Internet of Things (IoT) and how smarter devices — the things in the IoT — are changing the world. Another hot tech topic is the cloud in all of its forms: cloud storage, cloud-based apps, cloud-powered mobile devices, cloud-hosted virtual machines and other applications.

While there may be much talk about the IoT and cloud services, they have much more to offer than consumer-grade conveniences. A fusion of IoT and cloud technologies has specific applications in the industrial automation sector, creating the Industrial IoT (IIoT). Unquestionably, cloud-based SCADA software provides an ideal gateway to deliver practical and actionable IIoT information to those who need it.

Most IoT discussions to date have focused more on commercial than industrial implementations, but according to a GE/Accenture white paper, this focus should be changed to favour the IIoT because “data created by industrial equipment such as wind turbines, jet engines and MRI machines … holds more potential business value on a size-adjusted basis than other types of Big Data associated with the social Web, consumer Internet and other sources”.¹

Consumer-focused discussions about the IoT often revolve around refrigerators and coffee pots chattering with each other, or maybe reporting some details to their users. However, for IoT applications to move beyond curiosities and parlour tricks and into the realm of usefulness, the bits and bytes of available data must be served up within a pertinent context and formed into actionable information.

Harnessing cloud capabilities to harvest IIoT factory data and then distribute it to users is a powerful combination. Cloud-based SCADA software is an ideal platform to act as an IIoT gateway, empowering customers to use information and reap significant benefits.

Interfacing to existing automation systems

One overlooked reality is that factories, process plants, OEM equipment, materials handling systems and remote facilities are often actually quite a bit smarter than often realised. Most of these systems are automated by various types and vintages of computer-based control and monitoring systems. This means the foundations are in place for large amounts of data to be provided to cloud-based systems.

Sometimes the biggest challenge is geographic, when a facility is fragmented into many islands of automation that are not yet integrated with each other or with higher level computing systems. Other times, a site has legacy or proprietary control and monitoring systems which are not readily tapped for data. Fortunately, there are many solutions available to address each of these situations in a cost-effective and scalable manner.

The good news is that the data available from automation systems is of the very best type for IIoT implementations. IIoT data can concisely define a system’s throughput and performance, and show where it is working well and where it is breaking down. And this is the kind of information that can be acted on to expose unexpected inefficiencies, enable improvements that make a factory work better and generate significant savings.

Crunching numbers or making connections

Perhaps it is important at this point to develop a distinction between a ‘data concentrator’ and a ‘cloud-based IIoT gateway’, since the two functions are related but distinct. Both are typically incorporated in a complete IIoT solution — data concentrators are closest to the data sources, while the gateway is closer to the data consumers.

Any factory-located automation or data acquisition system, however large or small, can act as a data concentrator. These distributed systems — whether they are PLCs, proprietary controllers or even HMIs — can touch a large number of I/O points. However, not every limit switch status needs to be reported to the outside world, even though such information might be critical to automation system operation.

Instead, what makes the most sense is for the local automation or data acquisition system to crunch the numbers and perform real-time control, and to consolidate only the most useful information. Sometimes this information is an actual field signal like a pressure or temperature, while in other cases this information is derived from calculations, alarming logic or other algorithms. Raw field signals are conditioned to remove noise and scaled into proper engineering units to make them most useful. Equipment operating modes and conditions also provide important information, but are not usually based strictly on I/O signals, and thus require some data preparation by the local automation system. Data concentrator sources can reside in a single facility, or be distributed over multiple geographical locations.

The resulting serviceable information is really what needs to be communicated to supervisory systems so that humans or higher level software can act accordingly. A cloud-based IIoT SCADA gateway is the connection system that aggregates one or more data concentrators and other data sources to perform the communication function from the concentrators to the data consumers.

In a sense, the SCADA gateway is also a concentrator of sorts. While the data concentrator pre-processes and refines various data streams locally, the gateway consolidates various data concentrator streams into a single, common accessibility platform.

For example, cloud-based SCADA systems can add intelligence to data by executing pre-programmed routines to show patterns and predict incidents before they occur. This can be done by applying certain business intelligence rules to the data.

Fourth time's a charm

Why are data concentrators and cloud-based IIoT SCADA gateways more relevant than ever? The quick answer is ‘Industry 4.0’, which is concerned with IIoT power and with increasing communications among devices, machines and humans via internet connectivity.

Creating true value is the goal of Industry 4.0, but how is this achieved? Deutsche Bank Research finds that factories, logistics and even products become smarter to support the required functionality. The concept encompasses “not only value creation per se, but also work organization, business models and downstream services. It does this by using information technology to link up production, marketing and logistics and thereby captures all resources, production facilities and warehousing systems. The reorganization thus extends from the energy supply and smart power grids through to advanced mobility concepts ...”.²

A cloud-based IIoT SCADA gateway occupies a space in the middle of the requisite Industry 4.0 technologies. Data is generated at IIoT devices, and it is consumed by mobile users and business applications. The gateway is what gathers all of the pre-processed information and makes it effectively available for end users or data consumers.

Another aspect to consider is who will be integrating the IIoT with the cloud. Traditionally, operations technology (OT) automation engineers have handled the control systems and related equipment, while information technology (IT) professionals have handled business computers and networks. The nature of data concentrators and cloud-based IIoT gateways is that the two disciplines now interact and actually overlap. Therefore, for effective IIoT implementations, the relationship between OT and IT must be carefully cultured and managed. The first step is to identify the data.

It’s all about the data

When it comes to smart manufacturing information, ‘more is better’ sometimes but ‘better is best’ all the time. This means that even though it is possible to transmit every possible signal, a better strategy is to make good decisions about what is provided to the gateway. It is important to remember that excessive data may become an intractable mass, blurring effective use of the valuable information buried within. Good data pre-processing choices will transform disorganised data into targeted and useful information.

Key characteristics of IIoT data are:

• Industrial systems can create a multitude of raw real-time field data.
• Automation systems can pre-process raw data to put this information into context.
• Data can be continuous, scheduled or event-driven.
• Established control systems are powerful enough to process and network field data, while IT systems handle processed data.
• Databases or other applications are needed to bridge the two systems.

The most straightforward data sources consist of process signals like flows, levels, pressures and temperatures. But what constitutes a ‘good’ value and what defines a ‘bad’ situation that requires attention? The system designer must provide enough information to put these types of signals into context.

Certainly high and low alarm thresholds can be established as identifying good and bad values, but alarming and logging doesn’t always tell the whole story in a way that can help to counter developing off-spec conditions. It might be more appropriate to identify process conditions as optimal, average or substandard — even if they are not in a fully alarmed situation. This higher order of pre-processing will flow through the gateway and allow users to make more effective decisions.

Analysing every source of industrial data in an operation can be a daunting task, so the key is to divide and conquer by initially selecting sources expected to provide the best value.

One strategy is to pick a few small and simple data sources and systems as a first project, even if they may not offer the absolute best return. An air compressor system might be a good example. When the test cases are proven, one can focus on more complex data that will help improve high-value product processing.

Consider the best way to elevate useful information to users. For instance, knowing whether a photoelectric sensor is on or off on a conveyor may not be very helpful at a supervisory level, but counting how many items passed a checkpoint during the last rolling hour or during a shipping campaign may describe the operation’s efficiency in a useful manner at a glance.

Sometimes it is not necessary to reach all the way down to an automation controller in order to obtain IIoT data. Many systems incorporate HMIs, operator interface terminals (OITs) and control systems which are primarily used to provide automation system visibility to operators, and to allow them to initiate commands. These products may actually be the preferred solution for smaller skid equipment where each package has its own controller and OIT.

As the data harvesting activity proceeds, keep in mind that IT systems are tailored to provide processed data. Common networking protocols and methods are quite good at handling large data blocks such as videos and computer files. This contrasts somewhat with the comparatively smaller-sized blocks of industrial data. OT and IT systems are still a good fit for interconnectivity, but these differences must be understood, and accounted for as required.

Databases are one method of pre-processing data on a larger scale and can represent an effective option for bridging OT systems to the IT level. Similarly, a dedicated application such as a third-party historian may be the right choice to archive large amounts of historical data and then perform calculations or reporting on it so that only the pertinent results are offered to the gateway.

Why look to the cloud?

There are many inherent benefits and features of using a cloud-based IIoT gateway, such as:

• Compatibility with legacy interfaces like RS-232/485 and contemporary fieldbus technologies.
• Ability to handle many common industrial protocols such as Modbus and EtherNet/IP as well as vendor-specific protocols.
• Operating via advanced TCP and UDP connectivity over various established media such as wired Ethernet, Wi-Fi and cellular data networks.
• Providing redundancy, local storage and store-and-forward capability.

Possibly the greatest characteristic is flexibility. Even though cloud-based configurations use the latest internet technology, they are modular enough to incorporate legacy media and communications methods. There are bridging devices available to empower such legacy devices to be useful IIoT data sources, by converting proprietary protocols to standard Ethernet-based outputs.

Although communication media and protocols are moving to standardisation, there are still many technologies in active service. Examples of industrial fieldbus technologies include Profibus, Foundation Fieldbus and DeviceNet — each implemented on a variety of media. Other protocols are somewhat tailored to specific industries, such as BACnet and LonWorks for building automation, and DNP for the power industry. Add to this the fact that some device manufacturers still use vendor-specific protocols and there remains a wide variety of communication methods.

Figure 1: Cloud-based interconnectivity.

Cloud-based gateways have the ability to roll up all these varied communication methods into a common platform. Each connection is translated as needed, so that the end user is presented with a unified structure. The cloud-based gateway itself uses common web protocols and advanced Ethernet, TCP and UDP connectivity to ensure required levels of performance.

Figure 1 depicts how cloud-based SCADA can act as a centralised pivot point for harvesting IIoT information from industrial automation systems using a wide variety of media and protocols.

Other capabilities expand the effectiveness of a cloud-based gateway. For instance, redundancy capabilities improve system uptime in the event of a failure. Similarly, local storage combined with store-and-forward capability allows information to be buffered during a failure and then transferred when service is restored. Even though IIoT information is less critical than direct local real-time control, users still demand reliable communications performance.

Conclusion

The IIoT is rising in prominence, perhaps even faster than the commercial IoT. Cloud technologies are more than up to the challenge of securely handling manufacturing data.

A cloud-based SCADA system can act as a centralised pivot point for harvesting IIoT information from industrial automation systems. Such a system harnesses all the performance and capabilities of today’s powerful internet applications, with enough flexibility to access almost any vintage of data source. Add to this the ability to reach out to connect data over many types of wired and wireless media, and it is evident that cloud-based SCADA is an ideal method to implement Industry 4.0 and fully harness the power of the IIoT.

References:

1. General Electric, Accenture 2015, Industrial Internet Insights Report for 2015, <https://www.gesoftware.com/sites/default/files/industrial-internet-insights-report.pdf>
2. Deutsche Bank Research 2014, Industry 4.0: Huge potential for value creation waiting to be tapped,  <http://www.dbresearch.com/servlet/reweb2.ReWEB;jsessionid=53FE0BAE9C5FC2C8A692E2B334E6E513.srv-net-dbr-com?rwsite=DBR_INTERNET_EN-PROD&rwobj=ReDisplay.Start.class&document=PROD0000000000335628>

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