Import/Export

model:loadModels(modelSources)

Load XML or packed models into the address space. The format is detected from the model content.

ModelSources:

Array of file paths, HTTP/HTTPS URLs, XML document strings, packed blob strings, readable objects, or chunk-producing functions.

For every new model, a new namespace is created with the next index after the last added namespace. Namespace index 0 is reserved for the default namespace ‘http://opcfoundation.org/UA/’. If model with same URI already exists, it will be merged with the new one.

XML specifications

model:loadXml(source)

Import one UANodeSet XML model into the writable address-space provider.

Source:

XML document string, readable object, or chunk-producing function.

Returns:

nil

Throws:

Error if the XML model cannot be parsed or imported.

model:exportXml(output[, namespaceURIs])

Export XML models to a filename, open file handle, or output callback. A callback is called with each generated XML chunk. If namespaceURIs is not provided, all namespaces are exported.

Output:

Filename, writable file handle, or callback function that receives XML string chunks. A caller-provided file handle is not closed.

NamespaceURIs:

Array of namespace URIs to export.

Returns:

nil

Throws:

Error if the model cannot be exported.

Memory optimized packed format

OPC UA adress space can be exported to a packed binary format that is optimized for memory usage and loading speed. Packed format is ready for use without any additional parsing or preprocessing.

model:exportPacked(output[, namespaceURIs])

Export a packed readonly address-space blob to a filename, open file handle, or output callback. A callback is called with each generated binary chunk. If namespaceURIs is not provided, all namespaces are exported.

Output:

Filename, writable file handle, or callback function that receives binary string chunks. A caller-provided file handle is not closed.

NamespaceURIs:

Array of namespace URIs to export.

Returns:

nil

Throws:

Error if the model cannot be packed.

The following example shows how to export packed XML models to the file:

Export packed models to the file.

  local model = ua.baseModel(config)

  local editor = model:edit()
  local objectsFolder = editor:objectsFolder()
  local sensor = editor:addObject("Sensor")
  sensor:addVariable("Temperature", {Type=ua.VariantType.Double, Value=20})
  sensor:addVariable("Humidity", {Type=ua.VariantType.Double, Value=50})
  sensor:addVariable("Pressure", {Type=ua.VariantType.Double, Value=1013.25})
  sensor:addVariable("Voltage", {Type=ua.VariantType.Double, Value=220})
  sensor:addVariable("Current", {Type=ua.VariantType.Double, Value=10})
  sensor:addVariable("Power", {Type=ua.VariantType.Double, Value=2200})
  sensor:addVariable("Frequency", {Type=ua.VariantType.Double, Value=50})

  local configurationObject = sensor:addObject("Configuration")
  configurationObject:addProperty("Address", {Type=ua.VariantType.String, Value="1"})
  configurationObject:addProperty("Port", {Type=ua.VariantType.UInt16, Value=1234})
  configurationObject:addProperty("Enabled", {Type=ua.VariantType.Boolean, Value=true})

  editor:save()

  model:exportPacked("packed_model.uapb", {config.applicationUri})

Full source

model:loadPacked(source)

Load a packed blob string as a readonly address-space provider.

Source:

Packed blob string.

Returns:

Loaded readonly provider.

Throws:

Error if the packed blob is invalid or cannot be linked.

Here is the example of loading packed XML models from the file:

Import packed model from file.

local ua = require("opcua.api")

local config = ua.serverConfig({
  endpointUrl = "opc.tcp://localhost:4841",
  applicationUri = "urn:realtimelogic.com:server",
  productUri = "urn:realtimelogic.com:server",
  applicationName = "Example Server",
  applicationType = ua.ApplicationType.Server,
})
local server = ua.newServer(config)
server:initialize()
server:loadModels({"packed_model.uapb"})

-- server:run()

server:shutdown()

Full source