Industrial networks are the humble foundation upon which an automation system is built. Often taken for granted, once a network is designed, installed and commissioned, there are other tasks engineers must tend to, not least of which include keeping their plant running at optimum efficiency. This reality means there are two points in the life of an industrial network where it gets the most attention: first, during specification, and later, if something goes wrong.
Choosing a network
Choosing an industrial network is only a trivial task if it is allowed to become one. Many questions arise when a new automation system is specified. “Which suppliers am I familiar with?” “What new technologies are out there?” “How much is all of this going to cost?” But rarely does someone ask: “Which industrial network should I choose?”
The answer to this question should be easy, but often isn’t because even deeper questions then arise. “What speeds and determinism are needed?” “Will other protocols run on the same network infrastructure?” “Are extras like functional safety or wireless relevant?”
Facing such questions underscores the fact that now, more than ever, the question of which industrial network you choose cannot to be overlooked. The reason these questions have become so important is because industrial automation is on the cusp of a transformation with the Industrial Internet of Things (IIoT). With so many IIoT possibilities available to industry, the focus for industry should be on future-proofing. After all, no one knows how all of this IIoT business will shake out. But like a home, future renovations made to the house won't matter if the foundation is solid.
Since the winners and losers in the race to IIoT dominance remain uncertain, a future-proof industrial network will allow you to have your cake and eat it too. This means that the network should be robust, yet flexible. Robustness means an industrial network can handle whatever timing requirements are thrown at it, no matter how demanding. Flexibility means an industrial network is not just a network unto itself (like traditional fieldbuses), but an infrastructure for other protocols as well.
This is a key point when it comes to IIoT uncertainty. As IT and OT networks converge, IT protocols are increasingly finding their way onto OT networks. Though this may seem to create an array of new questions about how to prepare your industrial network for the integration of certain IT protocols, the reality is that as long as the IT network protocols and your OT network protocols are based on open standards, it shouldn’t matter to a future-proof industrial network.
If something breaks
The other point in the lifecycle of an industrial network when it receives attention is if something goes wrong. Nine times out of 10, the root cause of network downtime is due to poor policies and procedures. For example, in some companies, the control engineers are responsible for the entire automation system, including network installation. In others, it is up to the electrician or the IT department to install the cabling. Without knowledgeable workers performing the network installation, proper procedures will likely not be followed. This can lead to wires without shielding, insulation being cut off, bending radii limits exceeded, poor grounding, etc. This is why we at Profibus/Profinet International (PI) continue to put so much effort into our design, installation and commissioning guidelines for Profinet.
Another example of following poor procedures is how people treat the network. OT networks are not the same as IT networks. Take security, for instance. In IT networks, the priorities, in order, are: confidentiality, integrity and availability. In OT networks, the priorities are reversed: availability, integrity and confidentiality. Proper training is required to ensure that industrial networks are not only designed, installed and commissioned correctly, but that they are also treated properly.
Proof of being future-proof
If robustness and flexibility are the keys to a future-proof industrial network, there is one technology on the horizon that stands to make a big impact: Time-Sensitive Networking (TSN). The IEEE organization is taking many of the concepts formalized in Profinet IRT (Isochronous Real Time) and standardizing them in a new version of Ethernet called TSN. Therefore, companies looking to truly future-proof their industrial networks should choose a network that plans to utilize TSN from the device level to the machine level, up to the plant level. This technology will not be available tomorrow, but look for it in the coming months and years. It will provide future converged IT/OT networks a harmonized footing and ease possible pain points by providing robustness and flexibility.
The robustness and flexibility in Profinet to handle new developments like TSN is nothing new. From the outset, the protocol was created to be not only fast and deterministic for control, but an open network for other standard protocols that can handle anything from the need for microsecond-level speeds to providing an open infrastructure for TCP/IP or OPC UA.