Part 14 of Data Communication for Industrial IoT
Cloud computing can be quite useful in industrial systems to gather data and do supervisory control in some application spaces. “Big data” services help managers and engineers to locate inefficiencies, coordinate predictive maintenance, and boost productivity. The cloud model of software as a service (SaaS) offers a convenient way to add new functionality to existing systems, and it shifts costs from capital to operating expenses.
Despite the advantages of cloud systems, system integrators and key decision-makers in industrial facilities are reluctant to try it. Some of the reasons for this might include:
- License enforcement — “Will this cloud-based system be used to ensure software license compliance, in the same way my kids need an internet connection to play a single-player computer game?”
- Vendor lock-in — “If all the processing power of the system is in the cloud service, how can I switch services?”
- No edge processing — “There are too many cloud services that are basically just Internet-accessible databases. That’s not flexible enough for me.”
- Security — “Once my data leaves my plant, is it safe from prying eyes? And if I connect my plant to the cloud, will my plant be open to attack?”
- Loss of connectivity — “If my Internet connection goes down, will I lose my ability to control my plant?”
So should we avoid cloud services altogether? No. They provide capability and efficiency you can’t get any other way. In addition to data-gathering, cloud services can be used to support remote connectivity over the Internet.
Cloud as Intermediary
If we link an operation center in one city to a production system in another, there must be a network. If we make a direct connection, then one or the other must accept an inbound connection from the Internet. Using a cloud system as an intermediary means that neither the operation center nor the production system needs to open its firewall, thereby improving security by moving the point of attack outside either system.
Limited Data Sets
Should IIoT devices send all of their data to the cloud? No, it’s usually not necessary. Only the data necessary for remote monitoring and control needs to be accessed. Device information is not monolithic – you should be able to pick and choose what the cloud has access to.
Support for Local Capability
But what happens when cloud is not available? What happens if a cloud provider goes out of business (think Google/NEST Revolv)? The system should degrade in a way that essential functions still remain available. The goal should be to support fundamental local capability, enhanced with cloud services. We should still be able to use our devices when the Internet is not available.
Like most things in life, the cloud has its strong points and its weaknesses. The most successful implementations will take full advantage of the strong points, and design around the weaknesses. For industrial applications, that means keeping remote devices and in-plant systems behind closed firewalls and protecting them from any network slowdowns or outages. This can be accomplished through edge and fog processing mentioned previously, and/or by implementing a hybrid cloud, which we will discuss next.