OPC UA Client and Server

This documentation covers Real Time Logic’s Lua OPC UA stack, including the address-space model, Client/Server APIs, PubSub over MQTT, security, and ready-to-run examples.

Where to start

• New to this Lua stack: About opcua-lua

• New to OPC UA: OPC UA overview

• Learning the Lua APIs step by step: Learning OPC UA with Mako Server

• Working with nodes, types, and models: Address Space API

• Building an OPC UA client: Client

• Building an OPC UA server: Server

• Using MQTT PubSub: Publish Subscribe API

• Looking for ready-to-run examples: Examples

Documentation

• About opcua-lua
  • Why Lua
  • Where it fits
  • What to read next
• OPC UA overview
  • The address space
  • Types and instances
  • Common Client/Server services
  • Why it feels complex
  • Practical mental model
• Address Space API
  • Model methods
    • ua.emptyModel()
    • ua.baseModel()
  • Browser
  • Editor
    • Object
    • ObjectType
    • Variable
    • VariableType
    • Enum
    • Structure
    • Method
  • Import/Export
• Client
  • Getting Started
    • Connecting to Server
    • Browsing Address Space
    • Reading Node Attributes
    • Closing Server Connection
    • Asynchronous Cosocket Mode
  • Client Authentication
    • Working with client sessions
    • Anonymous
    • User Name
    • x509 certificate
    • JWT, OAuth2, Azure
  • Address Space Browsing
    • Browsing by String NodeID
    • Detailed Parameters
  • Reading and Writing Data
    • Reading Attributes
      • Read parameters
      • Read Attributes Of One Node
      • Read Attributes Of Several Nodes
      • Read Variables Values
    • Writing Attributes
      • Write Parameters
      • Write example
    • Node Attribute
      • Base node attribute numbers
      • Object node attribute numbers
      • Object Type node attribute numbers
      • Variable node attribute numbers
      • Variable Type node attribute numbers
      • Reference Type node attribute numbers
      • Data Type node attribute numbers
      • Method node attribute numbers
      • View node attribute numbers
      • List of all attribute numbers
  • Adding Nodes
    • Node attributes
    • Folder and Variable nodes
      • ua.newFolderParams()
      • ua.newVariableParams()
    • Adding nodes example
    • New node common attributes
    • Object NodeAttributes
      • Object NodeAttributes example
  • HTTP Client
    • HTTP Examples
      • Binary Encoding
      • JSON Encoding
  • OPC UA Project Code Generator
    • Initializing a client
  • Client API
    • Constructor
      • ua.newClient()
      • Client configuration table
    • client:connect
    • client:openSecureChannel
    • client:findServers
    • client:getEndpoints
    • client:createSession
    • client:activateSession
    • client:browse
    • client:read
    • client:write
    • client:addNodes
    • client:translateBrowsePaths
    • client:createSubscription
    • client:call
    • client:renewSecureChannel
    • client:checkSecureChannel
    • client:connected
    • client:closeSession
    • client:closeSecureChannel
    • client:disconnect
    • Message callback
      • msgCallback()
• Server
  • Getting Started with Server
    • Creating a Server
    • Adding Nodes on server
    • Starting the Server
    • Stopping the Server
  • Configuration table
  • Exporting Device Data
    • Value Callback
      • callback()
    • Writing Callback Parameters
    • Reading Callback Parameters
    • Error reporting
    • Custom data source example
  • XML Models
    • Loading XML models
    • Export XML models
  • Server side authentication
    • Identity token policies
    • Authentication callback
    • Anonymous token
    • User Name and password
    • X509 user certificate
    • Issued tokens
  • OPC UA Server Project Code Generator
    • Initializing a server
  • HTTP Server
    • Example
  • Server API
    • Server Constructor
      • ua.newServer()
      • Server default configuration
      • Server custom configuration
    • server:initialize
    • server:run
    • server:shutdown
    • server:addNodes
    • server:browse
    • server:read
    • server:write
    • server:setValueCallback
    • server:setWriteHook
      • writeHook()
    • server:loadXmlModels
    • server:createNamespace
    • server:exportXmlModels
• Publish Subscribe API
  • Client/Server vs PubSub over MQTT
    • OPC UA Client/Server
    • OPC UA PubSub over MQTT
    • Comparison
    • Choosing the right model
  • MQTT PubSub API
    • MQTT broker selection
    • MQTT Client constructor
      • ua.newMqttClient()
    • MQTT Connect
    • MQTT subscribe
      • messageCallback()
    • MQTT publishing
  • MQTT PubSub Examples
    • Monitoring OPC UA server changes
    • Publishing data to MQTT broker
    • Subscribing to MQTT messages
  • UADP Message
    • Common Fields
      • GroupHeader
      • SecurityHeader
    • UADP DataSetMessage
    • UADP AnnouncementMessage
      • DATASET_METADATA
      • Metadata
      • Metadata Fields
• Examples
  • Learning OPC UA with Mako Server
    • Run the tutorial examples
    • Run the PubSub tutorial examples
    • 1. Minimal server
    • 2. Add a folder
    • 3. Add variables
    • 4. Write a variable
    • 5. Use a value callback
    • 6. Read with a local client
    • 7. Write with a local client
    • 8. Call a method
    • 9. Define a structure type
    • 10. Publish JSON with MQTT PubSub
    • 11. Publish binary UADP with MQTT PubSub
    • 12. Publish an OPC UA server node
    • More advanced PubSub examples
    • Next steps
  • How to Connect Third-Party Clients
    • UAExpert
    • ProSys OPC UA
    • dataFEED OPCUA
  • ESP32 Microcontroller Examples
    • Ready-to-run OPC UA Server Example
    • Ignition SCADA
      • Add the ESP32 OPCUA server to Ignition
      • Ready-to-use Ignition Visualization Project
• Logging subsystem
• Secure Policy
  • None
  • Basic128Rsa15
  • Aes128_Sha256_RsaOaep
  • Basic256Sha256
  • Establishing secure connection
• Application Certificate
  • Creating certificate with xlua
  • Creating OpenSSL certificate
• Data Types
  • Built-in Types
  • LocalizedText
  • QualifiedName
  • NodeId
    • NodeId helpers
  • Variant
    • VariantType constants
  • DataValue
  • ExtensionObject
  • Service Structures
    • ActivateSessionResponse
    • AddNodesResponse
    • BrowseParameters
    • BrowseResult
    • CloseSecureChannelResponse
    • CloseSessionResponse
    • CreateSessionResponse
    • FindServersResponse
    • GetEndpointsResponse
    • OpenSecureChannelResponse
    • ReadResponse
    • WriteResponse
• OPC UA interoperability notes
  • NodeId representation depends on the encoding
  • Compact binary NodeIds are encoding choices
  • Namespace indexes are local to an address space
  • NodeSet2 XML imports require namespace remapping
  • Practical guidance