OPC UA

Industrial automation over OPC UA: browse nodes, read and write values, call methods, and read history

Signs in with: Connection details
Runs on: Cloud or On-Prem Worker
Operations: 26
Ready-made triggers: 0

Connect OPC UA

In Neblex open Connect › Connections and click New Connection.
Search for OPC UA and give the connection a clear name.
Fill in the fields. Secret values are encrypted and never shown again.
Click Test, then Create Connection.

If the system is only reachable inside your network, choose an On-Prem Worker under Test from and run the flow on that Worker. See On-Prem Workers.

Field	What to enter
Endpoint URLRequired	The server's opc.tcp endpoint URL. The connection always uses this host, whatever host the server advertises.Example: `opc.tcp://plc.example:4840`
Security policyRequired	None sends everything unprotected. The legacy policies exist only for older devices.
Message securityRequired
Server certificate or thumbprintOptional	Required for Sign and Sign and encrypt: the server certificate (PEM or base64) or its SHA-1 or SHA-256 thumbprint, as Get endpoints shows it. Only this certificate is trusted.
Client application certificateOptional	Optional PEM certificate the server trusts for this client. Leave empty to use a certificate generated for each session (for servers that accept new clients).
Client application private keyOptionalSecret	The PEM RSA private key of the client application certificate.
Client application URIOptional	Must equal the URI in the client application certificate.Example: `urn:neblex:integration-fabric:opcua-client`
Sign in withRequired
User nameOptional
PasswordOptionalSecret
User certificateOptional	The PEM or base64 X.509 certificate that identifies the user.
User private keyOptionalSecret
Issued tokenOptionalSecret	A token from the identity provider the server names, such as a JSON Web Token.
Session timeout (ms)Optional	How long the server keeps an idle session; the server may revise it.
Keep-alive interval (ms)Optional	How often an idle session proves it is alive. Keep it well below the session timeout.
Secure channel lifetime (ms)Optional	How long one secure channel key lasts before it is renewed.
Preferred localesOptional	Example: `en-US, de-DE`

Use it in a flow

Open a flow, open the node library and search for OPC UA.
Drag it onto the canvas and choose an Operation and your connection.
Map the operation's fields from earlier steps, or click Map with Matt.
Use Test this step to see what it returns, then save.

To start a flow from OPC UA without a ready-made trigger: a Poll for changes trigger can check one of its list operations on a schedule and pass on only what is new; if OPC UA can send webhooks, a Webhook trigger receives them at its own URL.

Operations

26 operations in 8 groups. Each one is a step you can add to a flow.

Attributes5

Read`read`		Read an attribute of one or many nodes in one request, split by the server's operation limits (Read).
Read a value`readValue`		Read the value of one variable with its built-in and declared data type.
Read node attributes`readAttributes`		Read every attribute of a node, or the ones named, into one record.
Write`write`		Write a value or attribute of one node, converted to the node's data type (Write).
Write many`writeMultiple`		Write several nodes in one request, split by the server's operation limits; each result is returned.

Connection1

Test the connectionping Open a session with the configured security and sign-in and read the server status.

Discovery3

Find servers`findServers`		List the servers a server or discovery server knows (FindServers).
Find servers on the network`findServersOnNetwork`		List the servers a local discovery server found on the network, page by page (FindServersOnNetwork).
Get endpoints`getEndpoints`		List the server's endpoints with their security, sign-in options and server certificate thumbprints (GetEndpoints).

History8

Delete history at times`historyDeleteAtTime`		Delete the stored values at given times (HistoryUpdate delete at time).
Delete history range`historyDeleteRaw`		Delete stored values between two times (HistoryUpdate delete raw or modified).
Delete stored events`historyDeleteEvents`		Delete stored events by their event IDs (HistoryUpdate delete events).
Read aggregated history`historyReadProcessed`		Read aggregates such as Average, Minimum, Maximum or Count over intervals, page by page (HistoryRead processed).
Read event history`historyReadEvents`		Read stored events of a notifier between two times with the chosen fields, page by page (HistoryRead events).
Read history at times`historyReadAtTime`		Read the values at given times, interpolated where needed (HistoryRead at time).
Read raw history`historyReadRaw`		Read stored values between two times, page by page through every continuation point (HistoryRead raw or modified).
Update history`historyUpdateData`		Insert, replace, update or remove stored values of a node (HistoryUpdate data).

Methods1

Call a methodcall Call a method of an object with arguments converted to the method's declared argument types (Call).

Node management4

Add a node`addNodes`		Create an object, variable or any node in the server's address space (AddNodes).
Add a reference`addReferences`		Add a reference between two nodes (AddReferences).
Delete a reference`deleteReferences`		Delete a reference between two nodes (DeleteReferences).
Delete nodes`deleteNodes`		Delete nodes from the server's address space (DeleteNodes).

Server2

Read namespace array`readNamespaceArray`		List the server's namespace URIs with their indexes.
Read server array`readServerArray`		List the server URIs the server knows with their indexes.

Browse`browse`		List the references of a node, following every continuation point (Browse and BrowseNext), filtered by direction, reference type, node class and name.
Translate browse paths`translateBrowsePaths`		Resolve browse paths to NodeIds (TranslateBrowsePathsToNodeIds).