How OPC UA/DA continues to expand and change industrial networks
Tobey Strauch is an independent principal industrial controls engineer in Fremont, California. Her breadth of automation knowledge is remarkable, and she’s a frequent contributor to Control Design. Her take on open platform communications unified architecture (OPC UA) is unique and profound.
What have been the most significant advancements/changes in technology that have affected OPC UA acceptance/implementation in the past five years?
Tobey Strauch, independent principal industrial controls engineer: Inductive Automation made the push for an open supervisory-control-and-data-acquisition (SCADA) software and showed how easy OPC tag distribution could be. Fortunately, since they came on the scene, more people have come up with ways to decrease network congestion—using user profiles, domain profiles, putting tags and parameters in scan time phases. It’s also possible to limit tags at a global level and then establish tag updates based on changes or timing.
What is the most innovative or efficient OPC UA application you have ever seen or been involved with?
Tobey Strauch, independent principal industrial controls engineer: OPC lets us bring together different original equipment manufacturers (OEMs) from the field to a server level or cloud in a short amount of configuration/programming time. This means data can be acquired remotely, either for diagnostics or for control. Thus, maybe we are on the verge of work/life balance or blackout plant operations.
How has OPC UA benefitted from the proliferation of components from multiple suppliers in machinery?
Tobey Strauch, independent principal industrial controls engineer: It’s in the definition of “unified architecture.” This allows everyone with obsolete equipment to talk across new networks and develop improvements without having to do it all at once. If you can get the data, you have eyes to control it. I think we need more training and more understanding on the plant-floor level because we are losing some people when the software layers get added.
Can you explain how Industry 4.0 initiatives or the Industrial Internet of Things has impacted the use of OPC UA in manufacturing?
Tobey Strauch, independent principal industrial controls engineer: I think industrial applications probably influence the Industrial Internet of Things more, based on the need for having easy communications across platforms. Also, hardware is allowing us to do this based on Ethernet capacity. Now that Ethernet is going to single pair with power and communications, the sky is the limit.
Do you find OPC UA more useful in small embedded systems of larger cloud-based applications?
Tobey Strauch, independent principal industrial controls engineer: I find OPC to be convenient in either case. Two things you must ask:
• Where is your device located?
• Where do you want that device data?
We are no longer limited by field, demarcation, IT-OT convergence or a motor control center (MCC). What the question becomes is: Do I have a switch in the vicinity?
I can have a vibration sensor on an oil rig in the Gulf of Mexico register a 14.6 mA value; a supervisory-control-and-data-acquisition (SCADA) system in Texas show an alarm; and a reliability engineer in Norway, say, “What are we going to do about it?” within an hour or less.
Take it to the next level: automatically generate a maintenance ticket, and a computer dispatches a tech to verify/validate/fix what the computer saw. This is what OPC UA gives us.
However, OPC UA/data access (DA) is not good for transfer over networks, so OPC UA/DA must be converted either on the OT side or the IT side, or proper tunneling must be used. ABB uses Cogent DataHub. Thus, use of OPC adds a complication for the data. Hardware guys may complain about speed if you have two-way control.
How have the security and scalability of OPC UA made it more user-friendly?
Tobey Strauch, independent principal industrial controls engineer: This is yet to be seen, I think. It’s so individually driven based on company policies. OPC UA means that the networks need to be tighter, so to speak, as far as security. We must isolate operations and data collection and then whitelist users via firewalls and network isolation based on machines, based on users, based on functionality.
I think we have huge gaps, in that there is not a push for making strong demarcation points and then allowing operations networks to shut off the information technology connection if there is a breach. Also, there are not standards being applied, unless it’s demanded by the industry, based on safety or applications like chemicals or nuclear.
What future innovations will impact the use of OPC UA in manufacturing operations?
Tobey Strauch, independent principal industrial controls engineer: I think OPC UA opens the door IO-Link and other protocols are going to service. Why? Hardware changes will allow it, ENet is going to two wires, and open architecture is becoming more mainstream.
Anything else that you would like to add about OPC UA?
Tobey Strauch, independent principal industrial controls engineer: Framework. We need to understand the OPC UA framework to use it properly and securely. People do not teach this; controls engineers must learn it. Traditional hardware guys will balk at it, so up-to-date applications may be slow. However, there is a lot more OPC out there today than there was 10 years ago.
Tell us about one of your organization’s state-of-the-art OPC-certified products.
Tobey Strauch, independent principal industrial controls engineer: My current customer uses an updated RSLinx OPC server with OPC user groups. This is known as FactoryTalk Linx now, and not the free version. Rockwell Automation went to great lengths in the past few years to improve its data-acquisition software and configurability for communication with non-Rockwell devices.
If you use a Rockwell OPC server, then you get quick connection to common-industrial-protocol (CIP) devices, but then the capability to talk to OPC components, regardless of the OEM.
