Concepts > QuickOPC Concepts > QuickOPC Development Models > Imperative Programming Model > Imperative Programming Model for OPC Data (Classic and UA) > Browsing for Information (OPC Data) > Browsing for OPC Classic Servers |
If you want to retrieve a list of OPC Data Access servers registered on a local or remote computer, call the BrowseServers method, passing it the name or address of the remote machine (use empty string for local computer).
In QuickOPC.NET, you will receive back a ServerElementCollection object. If you want to connect to this OPC server later in your code by calling other methods, use the built-in conversion of ServerElement to a String or ServerDescriptor, and pass the resulting string as a serverClass or a serverUrl argument either directly to the method call, or to a constructor of ServerDescriptor object.
In QuickOPC-COM, if you want to connect to some OPC server later in your code by calling other methods, obtain the value of ServerElement.ServerClass property, and pass the resulting string as a serverClass argument to the method call that accepts it.
Each ServerElement contains information gathered about one OPC server found on the specified machine, including things like the server’s CLSID, ProgID, vendor name, and readable description. For an OPC XML server, it contains its URL.
// This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine. // // 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.EasyOpc; using OpcLabs.EasyOpc.DataAccess; using OpcLabs.EasyOpc.OperationModel; namespace DocExamples.DataAccess._EasyDAClient { class BrowseServers { public static void Main1() { // Instantiate the client object. var client = new EasyDAClient(); ServerElementCollection serverElements; try { serverElements = client.BrowseServers(""); } catch (OpcException opcException) { Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message); return; } foreach (ServerElement serverElement in serverElements) Console.WriteLine($"ServerElements(\"{serverElement.ClsidString}\").ProgId: {serverElement.ProgId}"); } // Example output: // //ServerElements("c8a12f17-1e03-401e-b53d-6c654dd576da").ProgId: OPCLabs.KitServer.2 } }
' This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine. ' ' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . ' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET . ' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own ' a commercial license in order to use Online Forums, and we reply to every post. Imports OpcLabs.EasyOpc Imports OpcLabs.EasyOpc.DataAccess Imports OpcLabs.EasyOpc.OperationModel Namespace DataAccess._EasyDAClient Partial Friend Class BrowseServers Shared Sub Main1() Dim client = New EasyDAClient() Dim serverElements As ServerElementCollection Try serverElements = client.BrowseServers("") Catch opcException As OpcException Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message) Exit Sub End Try For Each serverElement In serverElements Console.WriteLine($"ServerElements(""{serverElement.ClsidString}"").ProgId: {serverElement.ProgId}") Next serverElement End Sub ' Example output: ' 'ServerElements("c8a12f17-1e03-401e-b53d-6c654dd576da").ProgId: OPCLabs.KitServer.2 End Class End Namespace
// This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine. // // Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . // 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. var Client = new ActiveXObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient"); var ServerElements = Client.BrowseServers("") for (var objEnum = new Enumerator(ServerElements) ; !objEnum.atEnd() ; objEnum.moveNext()) { var ServerElement = objEnum.item(); WScript.Echo("ServerElements(\"" + ServerElement.UrlString + "\").ProgId: " + ServerElement.ProgId); }
// This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine. // // 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. $Client = new COM("OpcLabs.EasyOpc.DataAccess.EasyDAClient"); try { $ServerElements = $Client->BrowseServers(""); } catch (com_exception $e) { printf("*** Failure: %s\n", $e->getMessage()); Exit(); } foreach ($ServerElements as $ServerElement) { printf("ServerElements(\"s\").ProgIds\n", $ServerElement->ClsidString, $ServerElement->ProgId); }
# This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine. # # The Python for Windows (pywin32) extensions package is needed. Install it using "pip install pypiwin32". # CAUTION: We now recommend using Python.NET package instead. Full set of examples with Python.NET is available! # # Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html . import win32com.client from pywintypes import com_error # Instantiate the client object client = win32com.client.Dispatch('OpcLabs.EasyOpc.DataAccess.EasyDAClient') # Perform the operation try: serverElements = client.BrowseServers('') except com_error as e: print('*** Failure: ' + e.args[2][1] + ': ' + e.args[2][2]) exit() # Display results for serverElement in serverElements: print('ServerElements("' + serverElement.ClsidString + '"): ' + serverElement.ProgId)
Rem This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine. 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 Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient") On Error Resume Next Dim ServerElements: Set ServerElements = Client.BrowseServers("") If Err.Number <> 0 Then WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description WScript.Quit End If On Error Goto 0 Dim ServerElement: For Each ServerElement In ServerElements WScript.Echo "ServerElements(""" & ServerElement.ClsidString & """).ProgId: " & ServerElement.ProgId Next
# This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine. # # 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.DataAccess import * from OpcLabs.EasyOpc.OperationModel import * # Instantiate the client object client = EasyDAClient() # Perform the operation try: serverElements = IEasyDAClientExtension.BrowseServers(client, '') except OpcException as opcException: print('*** Failure: ' + opcException.GetBaseException().Message) exit() # Display results for serverElement in serverElements: print('ServerElements("' + serverElement.ClsidString + '"): ' + serverElement.ProgId)
// This example shows all information available about categories that particular OPC servers do support. // // 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.EasyOpc; using OpcLabs.EasyOpc.AlarmsAndEvents; using OpcLabs.EasyOpc.DataAccess; using OpcLabs.EasyOpc.OperationModel; namespace DocExamples._ServerCategories { class General { public static void Main1() { // Instantiate the OPC-DA client object. var daClient = new EasyDAClient(); Console.WriteLine(); Console.WriteLine("OPC DATA ACCESS"); ServerElementCollection daServerElements; try { daServerElements = daClient.BrowseServers(); } catch (OpcException opcException) { Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message); return; } DumpServerElements(daServerElements); // Instantiate the OPC-A&E client object. var aeClient = new EasyAEClient(); Console.WriteLine(); Console.WriteLine("OPC ALARMS AND EVENTS"); ServerElementCollection aeServerElements; try { aeServerElements = aeClient.BrowseServers(); } catch (OpcException opcException) { Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message); return; } DumpServerElements(aeServerElements); } private static void DumpServerElements(ServerElementCollection serverElements) { foreach (ServerElement serverElement in serverElements) { Console.WriteLine($"Categories of \"{serverElement.ProgId}\":"); ServerCategories serverCategories = serverElement.ServerCategories; Console.WriteLine($" .OpcAlarmsAndEvents10: {serverCategories.OpcAlarmsAndEvents10}"); Console.WriteLine($" .OpcDataAccess10: {serverCategories.OpcDataAccess10}"); Console.WriteLine($" .OpcDataAccess20: {serverCategories.OpcDataAccess20}"); Console.WriteLine($" .OpcDataAccess30: {serverCategories.OpcDataAccess30}"); Console.WriteLine($" .ToString(): {serverCategories}"); } } // Example output: // //OPC DATA ACCESS //Categories of "OPCLabs.KitServer.2": // .OpcAlarmsAndEvents10: False // .OpcDataAccess10: True // .OpcDataAccess20: True // .OpcDataAccess30: True // .ToString(): (OpcDataAccess10, OpcDataAccess20, OpcDataAccess30) // //OPC ALARMS AND EVENTS //Categories of "OPCLabs.KitEventServer.2": // .OpcAlarmsAndEvents10: True // .OpcDataAccess10: False // .OpcDataAccess20: False // .OpcDataAccess30: False // .ToString(): (OpcAlarmsAndEvents10) } }
Rem This example shows all information available about categories that particular OPC servers do support. 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 Sub DumpServerElements(ByVal ServerElements) Dim ServerElement: For Each ServerElement In ServerElements WScript.Echo "Categories of """ & ServerElement.ProgID & """:" With ServerElement.ServerCategories WScript.Echo Space(4) & ".OpcAlarmsAndEvents10: " & .OpcAlarmsAndEvents10 WScript.Echo Space(4) & ".OpcDataAccess10: " & .OpcDataAccess10 WScript.Echo Space(4) & ".OpcDataAccess20: " & .OpcDataAccess20 WScript.Echo Space(4) & ".OpcDataAccess30: " & .OpcDataAccess30 WScript.Echo Space(4) & ".ToString(): " & .ToString() End With Next End Sub Dim DAClient: Set DAClient = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient") WScript.Echo WScript.Echo "OPC DATA ACCESS" On Error Resume Next Dim DAServerElements: Set DAServerElements = DAClient.BrowseServers("") If Err.Number <> 0 Then WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description WScript.Quit End If On Error Goto 0 DumpServerElements DAServerElements Dim AEClient: Set AEClient = CreateObject("OpcLabs.EasyOpc.AlarmsAndEvents.EasyAEClient") WScript.Echo WScript.Echo "OPC ALARMS AND EVENTS" On Error Resume Next Dim AEServerElements: Set AEServerElements = AEClient.BrowseServers("") If Err.Number <> 0 Then WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description WScript.Quit End If On Error Goto 0 DumpServerElements AEServerElements
// This example shows all information available about OPC servers. // // 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.EasyOpc; using OpcLabs.EasyOpc.DataAccess; using OpcLabs.EasyOpc.OperationModel; namespace DocExamples._ServerElement { class General { public static void Main1() { // Instantiate the client object. var client = new EasyDAClient(); ServerElementCollection serverElements; try { serverElements = client.BrowseServers(); } catch (OpcException opcException) { Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message); return; } foreach (ServerElement serverElement in serverElements) { Console.WriteLine($"Information about server \"{serverElement}\":"); Console.WriteLine($" .ServerClass: {serverElement.ServerClass}"); Console.WriteLine($" .ClsidString: {serverElement.ClsidString}"); Console.WriteLine($" .ProgId: {serverElement.ProgId}"); Console.WriteLine($" .Description: {serverElement.Description}"); Console.WriteLine($" .Vendor: {serverElement.Vendor}"); Console.WriteLine($" .ServerCategories: {serverElement.ServerCategories}"); Console.WriteLine($" .VersionIndependentProgId: {serverElement.VersionIndependentProgId}"); } // Example output: // //Information about server "opcda:OPCLabs.KitServer.2%7Bc8a12f17-1e03-401e-b53d-6c654dd576da%7D": // .ServerClass: OPCLabs.KitServer.2 // .ClsidString: c8a12f17-1e03-401e-b53d-6c654dd576da // .ProgId: OPCLabs.KitServer.2 // .Description: OPC Labs Kit Server // .Vendor: OPC Labs, http://www.opclabs.com // .ServerCategories: (OpcDataAccess10, OpcDataAccess20, OpcDataAccess30) // .VersionIndependentProgId: OPCLabs.KitServer } } }
Rem This example shows all information available about OPC servers. 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 Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient") On Error Resume Next Dim ServerElements: Set ServerElements = Client.BrowseServers("") If Err.Number <> 0 Then WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description WScript.Quit End If On Error Goto 0 Dim ServerElement: For Each ServerElement In ServerElements WScript.Echo "Information about server """ & ServerElement & """:" With ServerElement WScript.Echo Space(4) & ".ServerClass: " & .ServerClass WScript.Echo Space(4) & ".ClsidString: " & .ClsidString WScript.Echo Space(4) & ".ProgId: " & .ProgId WScript.Echo Space(4) & ".Description: " & .Description WScript.Echo Space(4) & ".Vendor: " & .Vendor WScript.Echo Space(4) & ".ServerCategories.ToString(): " & .ServerCategories.ToString() WScript.Echo Space(4) & ".VersionIndependentProgId: " & .VersionIndependentProgId End With Next
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