OPC UA (Object Types)¶
OPC UA object types define class like structures in OPC UA namespace that can be instanciated and added to the server address space. For more details on OPC UA Object Types please refer to: <https://reference.opcfoundation.org/v104/Core/docs/Part3/5.5.2/>
It is possible to create a instance of an objecttype by using the resource
type Cybus::Node::OpcuaObject
Example Commissioning File¶
Download: opcua-objecttype-example.yml
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | ---
description: demo for OPC UA objecttype nodes
metadata:
name: OPC UA Objecttypes demo
resources:
opcuaServer:
type: Cybus::Server::Opcua
properties:
alternateHostname: 192.168.178.46
securityModes: ['None', 'SignAndEncrypt']
nodesetFiles: ['di', 'machinery', 'machineTool']
securityPolicies: ['None', 'Basic256Sha256']
allowAnonymous: true
port: 4841
parentNodeRoot:
type: Cybus::Node::Opcua
properties:
parent: !ref opcuaServer
browseName: cybus
nodeId: ns=1;s=cybus
nodeType: Object
#######################################################
#
# Sample of an insance of an
# machine tool type. The type "MachineToolType" is
# defined in the MachineTool Umati namespace
#
#######################################################
testMachineToolType:
type: Cybus::Node::OpcuaObject
properties:
parent: !ref parentNodeRoot
browseName: MyMachineToolTypeTest
objectTypeName: MachineToolType
sourceNamespaceUrl: 'http://opcfoundation.org/UA/MachineTool/'
|
Output Format¶
The server provides the structure of the objecttyes and it’s values as a json structure as the example:
{
"ObjectTypeSample": {
"_children": {
"OperationMode": {
"_children": {
"ChildExample": {
"_children": {},
"_metadata": {
"nodeClass": "Variable",
"dataType": "Int64"
},
"_value": "1883344340925958233434349340394"
}
}
},
"_metadata": {
"nodeClass": "Variable",
"dataType": "Int32"
},
"_value": 0
}
},
"_metadata": {
"nodeClass": "Object"
}
}
_metadata |
contains all metadata on an node. The nodeclass corresponds to the node-opcua Nodeclass enum documented here: <http://node-opcua.github.io/api_doc/2.0.0/enums/nodeclass.html> On nodes of type “Variable” the dataType entry indicates the OPC UA native data type documented here: <http://node-opcua.github.io/api_doc/2.0.0/enums/datatype.html> |
_children |
contains child objects in the OPC UA object tree |
_value |
cotains the plain serialized value as JSON |
Writing Updates¶
Writing updates to the opc ua object type can be achieved by publishing to the <ObjectNodeName>/write topic. The same json structure can be used with updated data in the _value items. For data updates on U/INT64 please review the section on BigInt datatypes in OPC UA Server documentation. It is not necessary to update the complete structure. You can also only write a json structure that contains the direct value update. To update all values for the example structure above, only the following structure would be required:
{
"ObjectTypeSample": {
"_children": {
"OperationMode": {
"_children": {
"ChildExample": {
"_value": "50000000000000"
}
},
"_value": 10
}
}
}
}