OT
OPC UA security: modes, certificates and trust lists
Do not leave an OPC UA connection at “it works”. Treat security mode, certificate trust and user authentication as separate decisions.
Define the access boundary of an OT AI pilot
A starting architecture that separates reading, recommendations and control authority.
In short
- A first OT AI pilot can read data and advise engineers without writing commands to production systems.
- Recommendations should be presented with supporting evidence, timestamp and model version, and model text must not be turned directly into PLC code or setpoints.
- Before launch, the pilot should rehearse stopping the service, losing the data feed and restoring the previous version.
Limit initial authority
A first pilot can read data and advise engineers without writing commands to production. Record the data source, access account and collection gateway. Treat control-system availability separately from analytics availability. Inspect dependencies so an unavailable model service cannot interrupt process control.
Draw the data path
Map the PLC or DCS, collection layer, intermediate network zone and analytics environment. Document direction, protocol, owner and purpose for each connection. Consider a bounded copy of necessary signals instead of broad network access. Site policy and risk assessment must determine the actual architecture.
Keep engineering approval in the workflow
Show supporting evidence, timestamp and model version with recommendations. Record acceptance or rejection reasons for evaluation. Do not turn model text directly into PLC code or setpoints. Existing change review, test environments and engineering approval procedures continue to apply.
Exercise recovery before launch
Test stopping the service, losing the data feed and restoring the previous version. Name the responsible person, record retention period and escalation route. This guide is not certification or a site-specific security assessment; it collects questions for designing the pilot.
Frequently asked
How do I limit data access for an OT AI pilot?
Record the data source, access account and collection gateway. Document direction, protocol, owner and purpose for each connection. Consider a bounded copy of the necessary signals instead of broad network access, and let site policy and risk assessment determine the actual architecture.
What should happen before an AI pilot goes live in a plant?
Rehearse stopping the service, losing the data feed and restoring the previous version. Name the responsible person, record retention period and escalation route. Keep existing change review, test environments and engineering approval procedures in place, since model suggestions do not bypass them.
Sources and further reading
Pilot steps in this guide are proposed engineering workflows. Examples do not constitute measured field performance.
Questions on this topic
Keep reading.
Full library
OT
IEC 62443 and OT Security: Zones, Conduits, and Best Practices
IEC 62443 is the reference standard for industrial automation and control system security. Here is how its zone and conduit model translates into concrete network decisions.
Reliability
Remaining useful life (RUL): report an interval, not one number
Learn how RUL is defined, what each of three common approaches needs as data, and how to report P10, P50 and P90 values with a worked trend calculation.