OPC UA / IEC 62541

Overview

OPC UA, published internationally as IEC 62541, is the vendor-neutral standard for moving data between industrial systems. It defines a service-oriented model where a server exposes its data as a structured, self-describing address space and clients read, write, browse, and subscribe to it over a secured channel. Security is built into the protocol rather than bolted on. Because it is platform-independent and widely adopted, OPC UA is the default interoperability requirement on most modern automation tenders, and a platform that speaks it as both client and server connects to existing SCADA, PLC, and historian systems without custom gateways.

Key requirements

Service-oriented information exchange

Expose data through a defined set of services (read, write, browse, subscribe) over a secure channel, independent of the underlying transport and the vendor on either end.

Structured address space

Present data as typed nodes (objects and variables) with stable node identifiers and namespaces, so a client can discover and navigate what a server offers rather than relying on out-of-band documentation.

Built-in security

Protect connections with message signing and encryption, certificate-based application trust, and user authentication, each selectable per connection to match the deployment.

Subscriptions and monitored items

Deliver value changes to clients as they happen, at an agreed sampling interval, instead of requiring constant polling.

How ControlBird aligns

Acts as both client and server

ControlBird connects to external OPC UA servers to consume their data, and exposes its own entities as OPC UA variable nodes for external clients. It can sit on either side of an integration, so it fits whether the existing system is the data source or the consumer.

Standards-based security

Connections support the OPC UA security policies and the Sign and SignAndEncrypt message modes, with anonymous or username and password identities. Certificates for signed and encrypted channels are issued and tracked through the built-in Certificate Manager rather than managed by hand.

Address-space mapping

Remote nodes are bound to entity fields by their node identifier, using either numeric (ns=2;i=42) or string (ns=1;s=Temperature) form, and ControlBird publishes its own entities under browseable folder paths. The Device Manager can browse a remote server’s address space while you configure the mapping, so you select nodes from a live tree instead of typing identifiers blind.

Change-driven subscriptions

Mappings can subscribe to monitored items at a configurable sampling interval so updates arrive as values change. If a server declines a subscription, ControlBird falls back to polling automatically, so data keeps flowing.

Scope you should plan around

ControlBird maps scalar values today. Complex OPC UA arrays and structures are not mapped, so integrations should be designed around scalar tags. We state this plainly so it can be confirmed against a tender’s data requirements up front.