// This example shows how to get value of multiple OPC XML-DA properties, and handle errors. // // Note that some properties may not have a useful value initially (e.g. until the item is activated in a group), which also the // case with Timestamp property as implemented by the demo server. This behavior is server-dependent, and normal. You can run // IEasyDAClient.ReadMultipleItemValues.Main.vbs shortly before this example, in order to obtain better property values. Your // code may also subscribe to the items in order to assure that they remain active. // // Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . // OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp . // Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own // a commercial license in order to use Online Forums, and we reply to every post. using System; using OpcLabs.BaseLib.OperationModel; using OpcLabs.EasyOpc; using OpcLabs.EasyOpc.DataAccess; using OpcLabs.EasyOpc.DataAccess.OperationModel; namespace DocExamples.DataAccess.Xml { partial class GetMultiplePropertyValues { public static void Main1Xml() { // Instantiate the client object. var client = new EasyDAClient(); ServerDescriptor serverDescriptor = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx"; // Get the values of Timestamp and AccessRights properties of two items. ValueResult[] results = client.GetMultiplePropertyValues(new[] { new DAPropertyArguments(serverDescriptor, "Dynamic/Analog Types/Int", DAPropertyDescriptor.Timestamp), new DAPropertyArguments(serverDescriptor, "Dynamic/Analog Types/Int", DAPropertyDescriptor.AccessRights), new DAPropertyArguments(serverDescriptor, "Static/Analog Types/Double", DAPropertyDescriptor.Timestamp), new DAPropertyArguments(serverDescriptor, "Static/Analog Types/Double", DAPropertyDescriptor.AccessRights) }); for (int i = 0; i < results.Length; i++) { ValueResult valueResult = results[i]; if (valueResult.Exception is null) Console.WriteLine($"results({i}).Value: {valueResult.Value}"); else Console.WriteLine($"results({i}).Exception.Message: {valueResult.Exception.Message}"); } } } }
' This example shows how to get value of multiple OPC XML-DA properties, and handle errors. ' ' Note that some properties may not have a useful value initially (e.g. until the item Is activated in a group), which also the ' case with Timestamp property as implemented by the demo server. This behavior is server-dependent, and normal. You can run ' IEasyDAClient.ReadMultipleItemValues.Main.vbs shortly before this example, in order to obtain better property values. Your ' code may also subscribe to the items in order to assure that they remain active. ' ' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . ' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET . ' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own ' a commercial license in order to use Online Forums, and we reply to every post. Imports OpcLabs.BaseLib.OperationModel Imports OpcLabs.EasyOpc Imports OpcLabs.EasyOpc.DataAccess Imports OpcLabs.EasyOpc.DataAccess.OperationModel Namespace DataAccess.Xml Partial Friend Class GetMultiplePropertyValues Shared Sub Main1Xml() ' Instantiate the client object. Dim client = New EasyDAClient() Dim serverDescriptor As ServerDescriptor = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx" ' Get the values of Timestamp and AccessRights properties of two items. Dim results() As ValueResult = client.GetMultiplePropertyValues(New DAPropertyArguments() { New DAPropertyArguments(serverDescriptor, "Dynamic/Analog Types/Int", DAPropertyDescriptor.Timestamp), New DAPropertyArguments(serverDescriptor, "Dynamic/Analog Types/Int", DAPropertyDescriptor.AccessRights), New DAPropertyArguments(serverDescriptor, "Static/Analog Types/Double", DAPropertyDescriptor.Timestamp), New DAPropertyArguments(serverDescriptor, "Static/Analog Types/Double", DAPropertyDescriptor.AccessRights) }) For i = 0 To results.Length - 1 Dim valueResult As ValueResult = results(i) If valueResult.Exception Is Nothing Then Console.WriteLine($"results({i}).Value: {valueResult.Value}") Else Console.WriteLine($"results({i}).Exception.Message: {valueResult.Exception.Message}") End If Next i End Sub End Class End Namespace
# This example shows how to get value of multiple OPC XML-DA properties, and handle errors. # Note that some properties may not have a useful value initially (e.g. until the item is activated in a group), which also the # case with Timestamp property as implemented by the demo server. This behavior is server-dependent, and normal. You can run # IEasyDAClient.ReadMultipleItemValues.Main.vbs shortly before this example, in order to obtain better property values. Your # code may also subscribe to the items in order to assure that they remain active. # # Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . # OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python . # Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own # a commercial license in order to use Online Forums, and we reply to every post. # The QuickOPC package is needed. Install it using "pip install opclabs_quickopc". import opclabs_quickopc # Import .NET namespaces. from OpcLabs.EasyOpc import * from OpcLabs.EasyOpc.DataAccess import * from OpcLabs.EasyOpc.DataAccess.OperationModel import * # Instantiate the client object. client = EasyDAClient() serverDescriptor = ServerDescriptor('http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx') # Get the values of Timestamp and AccessRights properties of two items. results = client.GetMultiplePropertyValues( [ DAPropertyArguments(serverDescriptor, DANodeDescriptor('Dynamic/Analog Types/Int'), DAPropertyDescriptor.Timestamp), DAPropertyArguments(serverDescriptor, DANodeDescriptor('Dynamic/Analog Types/Int'), DAPropertyDescriptor.AccessRights), DAPropertyArguments(serverDescriptor, DANodeDescriptor('Static/Analog Types/Double'), DAPropertyDescriptor.Timestamp), DAPropertyArguments(serverDescriptor, DANodeDescriptor('Static/Analog Types/Double'), DAPropertyDescriptor.AccessRights) ]) for i, valueResult in enumerate(results): if valueResult.Exception is None: print('results[', i, '].Value: ', valueResult.Value, sep='') else: print('results[', i, '].Exception.Message: ', valueResult.Exception.Message, sep='')
The example below is a bit more complex, and combines the ability to browse for items with getting the the data type property for each of the items obtained, for OPC XML-DA Servers.
// This example shows how to obtain a data type of all OPC XML-DA items under a branch. // // Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . // OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp . // Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own // a commercial license in order to use Online Forums, and we reply to every post. using System; using System.Linq; using OpcLabs.BaseLib.ComInterop; using OpcLabs.BaseLib.OperationModel; using OpcLabs.EasyOpc; using OpcLabs.EasyOpc.DataAccess; using OpcLabs.EasyOpc.DataAccess.AddressSpace; namespace DocExamples.DataAccess.Xml { partial class GetMultiplePropertyValues { public static void DataTypeXml() { // Instantiate the client object. var client = new EasyDAClient(); ServerDescriptor serverDescriptor = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx"; // Browse for all leaves under the "Static/Analog Types" branch DANodeElementCollection nodeElementCollection = client.BrowseLeaves(serverDescriptor, "Static/Analog Types"); // Create list of node descriptors, one for each leaf obtained DANodeDescriptor[] nodeDescriptorArray = nodeElementCollection .Where(element => !element.IsHint) // filter out hint leafs that do not represent real OPC items (rare) .Select(element => new DANodeDescriptor(element)) .ToArray(); // Get the value of DataType property; it is a 16-bit signed integer ValueResult[] valueResultArray = client.GetMultiplePropertyValues(serverDescriptor, nodeDescriptorArray, DAPropertyIds.DataType); for (int i = 0; i < valueResultArray.Length; i++) { DANodeDescriptor nodeDescriptor = nodeDescriptorArray[i]; // Check if there has been an error getting the property value ValueResult valueResult = valueResultArray[i]; if (!(valueResult.Exception is null)) { Console.WriteLine("{0} *** Failure: {1}", nodeDescriptor.NodeId, valueResult.Exception.Message); continue; } // Convert the data type to VarType var varType = (VarType)(short)valueResult.Value; // Display the obtained data type Console.WriteLine("{0}: {1}", nodeDescriptor.ItemId, varType); } } } }
' This example shows how to obtain a data type of all OPC XML-DA items under a branch. ' ' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . ' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET . ' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own ' a commercial license in order to use Online Forums, and we reply to every post. Imports OpcLabs.BaseLib.ComInterop Imports OpcLabs.BaseLib.OperationModel Imports OpcLabs.EasyOpc Imports OpcLabs.EasyOpc.DataAccess Namespace DataAccess.Xml Friend Class GetMultiplePropertyValues Public Shared Sub DataTypeXml() Dim client = New EasyDAClient() Dim serverDescriptor As ServerDescriptor = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx" ' Browse for all leaves under the "Simulation" branch Dim nodeElementCollection = client.BrowseLeaves(serverDescriptor, "Static/Analog Types") ' Create list of node descriptors, one for each leaf obtained ' filter out hint leafs that do not represent real OPC items (rare) Dim nodeDescriptorArray() As DANodeDescriptor = nodeElementCollection _ .Where(Function(element) Not element.IsHint) _ .Select(Function(element) New DANodeDescriptor(element)) _ .ToArray() ' Get the value of DataType property; it is a 16-bit signed integer Dim valueResultArray() As ValueResult = client.GetMultiplePropertyValues(serverDescriptor, nodeDescriptorArray, DAPropertyIds.DataType) For i = 0 To valueResultArray.Length - 1 Dim nodeDescriptor = nodeDescriptorArray(i) ' Check if there has been an error getting the property value Dim valueResult As ValueResult = valueResultArray(i) If valueResult.Exception IsNot Nothing Then Console.WriteLine("{0} *** Failure: {1}", nodeDescriptor.NodeId, valueResult.Exception.Message) Continue For End If ' Convert the data type to VarType Dim varType = CType(CShort(valueResult.Value), VarType) ' Display the obtained data type Console.WriteLine("{0}: {1}", nodeDescriptor.ItemId, varType) Next i End Sub End Class End Namespace
// This example shows how to obtain a data type of all OPC XML-DA items under a branch. // // Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . // OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-OP . // Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own // a commercial license in order to use Online Forums, and we reply to every post. class procedure GetMultiplePropertyValues.DataTypeXml; var Arguments: OleVariant; BrowseParameters: _DABrowseParameters; Client: OpcLabs_EasyOpcClassic_TLB._EasyDAClient; Count: Cardinal; Element: OleVariant; I: Cardinal; PropertyArguments: _DAPropertyArguments; ServerDescriptor: _ServerDescriptor; NodeDescriptor: _DANodeDescriptor; // NodeDescriptorArray: Array of DANodeDescriptor; NodeElement: _DANodeElement; NodeElementCollection: _DANodeElementCollection; NodeElementEnumerator: IEnumVariant; ValueResult: _ValueResult; ValueResultArray: OleVariant; VarType: _VarType; begin ServerDescriptor := CoServerDescriptor.Create; ServerDescriptor.UrlString := 'http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx'; NodeDescriptor := CoDANodeDescriptor.Create; NodeDescriptor.ItemId := 'Static/Analog Types'; BrowseParameters := CoDABrowseParameters.Create; BrowseParameters.BrowseFilter := DABrowseFilter_Leaves; // Instantiate the client object Client := CoEasyDAClient.Create; // Browse for all leaves under the "Static/Analog Types" branch NodeElementCollection := Client.BrowseNodes( ServerDescriptor, NodeDescriptor, BrowseParameters); // Create list of node descriptors, one for aeach leaf obtained I := 0; Arguments := VarArrayCreate([0, NodeElementCollection.Count - 1], varVariant); NodeElementEnumerator := NodeElementCollection.GetEnumerator; while (NodeElementEnumerator.Next(1, Element, Count) = S_OK) do begin NodeElement := IUnknown(Element) as _DANodeElement; // filter out hint leafs that do not represent real OPC XML-DA items (rare) if Not NodeElement.IsHint then begin PropertyArguments := CoDAPropertyArguments.Create; PropertyArguments.ServerDescriptor := ServerDescriptor; PropertyArguments.NodeDescriptor := NodeElement.ToDANodeDescriptor; PropertyArguments.PropertyDescriptor.PropertyId.InternalValue := DAPropertyIds_DataType; Arguments[I] := PropertyArguments; I := I + 1; end; end; // SetLength(Arguments, I); // Get the value of DataType property; it is a 16-bit signed integer TVarData(ValueResultArray).VType := varArray or varVariant; TVarData(ValueResultArray).VArray := PVarArray( Client.GetMultiplePropertyValues(Arguments)); // Display results for I := VarArrayLowBound(ValueResultArray, 1) to VarArrayHighBound(ValueResultArray, 1) do begin ValueResult := IInterface(ValueResultArray[I]) as _ValueResult; // Check if there has been an error getting the property value if ValueResult.Exception <> nil then begin WriteLn(Format('s *** Failures', [Arguments[I].NodeDescriptor.NodeId, ValueResult.Exception.Message])); Continue; end; // Convert the data type to VarType VarType := CoVarType.Create; VarType.InternalValue := ValueResult.Value; // Display the obtained data type WriteLn(Format('s: s', [Arguments[I].NodeDescriptor.NodeId, VarType.ToString])); end; VarClear(ValueResultArray); VarClear(Arguments); end;
// This example shows how to obtain a data type of all OPC XML-DA items under a branch. // // Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . // OPC client and subscriber examples in PHP on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PHP . // Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own // a commercial license in order to use Online Forums, and we reply to every post. const DABrowseFilter_Leaves = 3; const DAPropertyIds_DataType = 1; $ServerDescriptor = new COM("OpcLabs.EasyOpc.ServerDescriptor"); $ServerDescriptor->UrlString = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx"; $NodeDescriptor = new COM("OpcLabs.EasyOpc.DataAccess.DANodeDescriptor"); $NodeDescriptor->ItemID = "Static/Analog Types"; $BrowseParameters = new COM("OpcLabs.EasyOpc.DataAccess.DABrowseParameters"); $BrowseParameters->BrowseFilter = DABrowseFilter_Leaves; $Client = new COM("OpcLabs.EasyOpc.DataAccess.EasyDAClient"); // Browse for all leaves under the "Static/Analog Types" branch $NodeElementCollection = $Client->BrowseNodes($ServerDescriptor, $NodeDescriptor, $BrowseParameters)->ToList(); $PropertyArgumentArray = array(); for ($i = 0; $i < $NodeElementCollection->Count(); $i++) { if (!($NodeElementCollection[$i]->IsHint)) // filter out hint leafs that do not represent real OPC items (rare) { $PropertyArguments = new COM("OpcLabs.EasyOpc.DataAccess.OperationModel.DAPropertyArguments"); $PropertyArguments->ServerDescriptor = $ServerDescriptor; $PropertyArguments->NodeDescriptor = $NodeElementCollection[$i]->ToDANodeDescriptor(); $PropertyArguments->PropertyDescriptor->PropertyId->InternalValue = DAPropertyIds_DataType; $PropertyArgumentArray[] = $PropertyArguments; } } // Get the value of DataType property; it is a 16-bit signed integer $valueResultArray = $Client->GetMultiplePropertyValues($PropertyArgumentArray); for ($i = 0; $i < count($valueResultArray); $i++) { // Check if there has been an error getting the property value $valueResult = $valueResultArray[$i]; if (!is_null($valueResult->Exception)) { printf("[s]: *** Failures\n", $PropertyArgumentArray[$i]->NodeDescriptor->NodeId, $valueResults->Exception->Message); continue; } // Convert the data type to VarType $VarType = new COM("OpcLabs.BaseLib.ComInterop.VarType"); $VarType->InternalValue = $valueResult->Value; // Display the obtained data type printf("[s]s\n", $PropertyArgumentArray[$i]->NodeDescriptor->NodeId, $VarType); }
Rem This example shows how to obtain a data type of all OPC XML-DA items under a branch. Rem REM Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . REM OPC client and subscriber examples in Visual Basic on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VB . REM Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own REM a commercial license in order to use Online Forums, and we reply to every post. Private Sub GetMultiplePropertyValues_DataTypeXml_Command_Click() OutputText = "" Dim serverDescriptor As New serverDescriptor serverDescriptor.UrlString = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx" Dim NodeDescriptor As New DANodeDescriptor NodeDescriptor.ItemId = "Static/Analog Types" Dim BrowseParameters As New DABrowseParameters BrowseParameters.BrowseFilter = DABrowseFilter_Leaves ' Instantiate the client object Dim client As New EasyDAClient ' Browse for all leaves under the "Static/Analog Types" branch Dim NodeElementCollection As DANodeElementCollection Set NodeElementCollection = client.BrowseNodes(serverDescriptor, NodeDescriptor, BrowseParameters) ' Create list of node descriptors, one for each leaf obtained Dim arguments() ReDim arguments(NodeElementCollection.Count) Dim i: i = 0 Dim NodeElement: For Each NodeElement In NodeElementCollection ' filter out hint leafs that do not represent real OPC XML-DA items (rare) If Not NodeElement.IsHint Then Dim PropertyArguments As New DAPropertyArguments Set PropertyArguments.serverDescriptor = serverDescriptor Set PropertyArguments.NodeDescriptor = NodeElement.ToDANodeDescriptor PropertyArguments.PropertyDescriptor.PropertyId.NumericalValue = DAPropertyIds_DataType Set arguments(i) = PropertyArguments Set PropertyArguments = Nothing i = i + 1 End If Next Dim propertyArgumentArray() ReDim propertyArgumentArray(i - 1) Dim j: For j = 0 To i - 1 Set propertyArgumentArray(j) = arguments(j) Next ' Get the value of DataType property; it is a 16-bit signed integer Dim valueResultArray() As Variant valueResultArray = client.GetMultiplePropertyValues(propertyArgumentArray) ' Display results For j = 0 To i - 1 Dim NodeDescriptor2 As DANodeDescriptor Set NodeDescriptor2 = propertyArgumentArray(j).NodeDescriptor Dim ValueResult As ValueResult: Set ValueResult = valueResultArray(j) ' Check if there has been an error getting the property value If Not ValueResult.Exception Is Nothing Then OutputText = OutputText & NodeDescriptor2.NodeId & " *** Failure: " & ValueResult.Exception.Message & vbCrLf Else ' Display the obtained data type Dim VarType As New VarType VarType.InternalValue = ValueResult.value OutputText = OutputText & NodeDescriptor2.NodeId & ": " & VarType & vbCrLf End If Next End Sub
Rem This example shows how to obtain a data type of all OPC XML-DA items under a branch. Rem Rem Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . Rem OPC client and subscriber examples in VBScript on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBScript . Rem Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own Rem a commercial license in order to use Online Forums, and we reply to every post. Option Explicit Const DABrowseFilter_Leaves = 3 Const DAPropertyIds_DataType = 1 Dim ServerDescriptor: Set ServerDescriptor = CreateObject("OpcLabs.EasyOpc.ServerDescriptor") ServerDescriptor.UrlString = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx" Dim NodeDescriptor: Set NodeDescriptor = CreateObject("OpcLabs.EasyOpc.DataAccess.DANodeDescriptor") NodeDescriptor.ItemID = "Static/Analog Types" Dim BrowseParameters: Set BrowseParameters = CreateObject("OpcLabs.EasyOpc.DataAccess.DABrowseParameters") BrowseParameters.BrowseFilter = DABrowseFilter_Leaves Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient") ' Browse for all leaves under the "Static/Analog Types" branch Dim NodeElementCollection: Set NodeElementCollection = client.BrowseNodes(serverDescriptor, nodeDescriptor, browseParameters) ' Create list of node descriptors, one for each leaf obtained Dim arguments() Redim arguments(nodeElementCollection.Count) Dim i: i = 0 Dim NodeElement: For Each NodeElement In NodeElementCollection ' filter out hint leafs that do not represent real OPC XML-DA items (rare) If Not NodeElement.IsHint Then Dim PropertyArguments: Set PropertyArguments = CreateObject("OpcLabs.EasyOpc.DataAccess.OperationModel.DAPropertyArguments") PropertyArguments.ServerDescriptor = ServerDescriptor PropertyArguments.NodeDescriptor = NodeElement.ToDANodeDescriptor PropertyArguments.PropertyDescriptor.PropertyId.InternalValue = DAPropertyIds_DataType Set arguments(i) = PropertyArguments i = i + 1 End If Next Dim propertyArgumentArray() ReDim propertyArgumentArray(i - 1) Dim j: For j = 0 To i - 1 Set propertyArgumentArray(j) = arguments(j) Next ' Get the value of DataType property; it is a 16-bit signed integer Dim valueResultArray: valueResultArray = client.GetMultiplePropertyValues(propertyArgumentArray) For j = 0 To i - 1 Dim NodeDescriptor2: Set NodeDescriptor2 = propertyArgumentArray(j).NodeDescriptor ' Check if there has been an error getting the property value If Not (valueResultArray(j).Exception Is Nothing) Then WScript.Echo NodeDescriptor2.NodeId & " *** Failure: " & valueResultArray(j).Exception.Message Else ' Display the obtained data type Dim VarType: Set VarType = CreateObject("OpcLabs.BaseLib.ComInterop.VarType") VarType.InternalValue = valueResultArray(j).Value WScript.Echo nodeDescriptor2.NodeId & ": " & VarType End If Next
# This example shows how to obtain a data type of all OPC XML-DA items under a branch. # # Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . # OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python . # Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own # a commercial license in order to use Online Forums, and we reply to every post. # The QuickOPC package is needed. Install it using "pip install opclabs_quickopc". import opclabs_quickopc # Import .NET namespaces. from OpcLabs.BaseLib.ComInterop import * from OpcLabs.EasyOpc import * from OpcLabs.EasyOpc.DataAccess import * from OpcLabs.EasyOpc.DataAccess.OperationModel import * from OpcLabs.EasyOpc.OperationModel import * serverDescriptor = ServerDescriptor('http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx') # Instantiate the client object. client = EasyDAClient() # Browse for all leaves under the "Static/Analog Types" branch try: nodeElementCollection = IEasyDAClientExtension.BrowseLeaves(client, serverDescriptor, DANodeDescriptor('Static/Analog Types')) except OpcException as opcException: print('*** Failure: ' + opcException.GetBaseException().Message) exit() # Create list of node descriptors, one for each leaf obtained. filteredNodeElements = filter(lambda element: not element.IsHint, nodeElementCollection) nodeDescriptorArray = list(map(lambda element: DANodeDescriptor(element), filteredNodeElements)) # Get the value of DataType property; it is a 16-bit signed integer. resultArray = IEasyDAClientExtension.GetMultiplePropertyValues(client, serverDescriptor, nodeDescriptorArray, DAPropertyDescriptor.FromInt64(DAPropertyIds.DataType)) # Display results for i, valueResult in enumerate(resultArray): nodeDescriptor = nodeDescriptorArray[i] # Check if there has been an error getting the property value. if valueResult.Exception is None: # Convert the data type to VarType. varType = VarType(valueResult.Value) # Display the obtained data type. print(nodeDescriptor.ItemId, ': ', varType, sep='') else: print(nodeDescriptor.ItemId, ' *** Failure: ', valueResult.Exception.Message) print() print('Finished')
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