How to Set the Response Delay for a PXE Service Point

Article
05/03/2011

Applies To: System Center Configuration Manager 2007, System Center Configuration Manager 2007 R2, System Center Configuration Manager 2007 R3, System Center Configuration Manager 2007 SP1, System Center Configuration Manager 2007 SP2

In Microsoft System Center Configuration Manager 2007, you set the operating system deployment PXE service point response delay by updating ResponseDelay embedded property. ResponseDelay specifies how long the delay should be for this PXE service point before it responds to computer requests when multiple PXE service points are used. By default, the Configuration Manager 2007 PXE service point will respond immediately to the network PXE requests.

The delay is provided by the PXE client, and it shows the time that has passed since the client started the PXE boot process (seconds elapsed since client began address acquisition or renewal process). A client sends requests to the server at intervals of 0 (default), 4, 8, 16, or 32 seconds.

To set the response delay for a PXE service point

Set up a connection to the SMS Provider. For more information, see About the SMS Provider in Configuration Manager.
Make a connection to the PXE service point resources section of the site control file.
Get the embedded properties.
Update the ResponseDelay embedded property.
Commit the changes to the site control file.

Example

The following example method sets the response delay for a PXE service point.

For information about calling the sample code, see Calling Configuration Manager Code Snippets.

Sub SetResponseDelay(connection,          _
                     context,           _
                     siteCode,               _
                     delay)
 
    ' Load site control file and get SMS PXE service point section.
    connection.ExecMethod "SMS_SiteControlFile.Filetype=1,Sitecode=""" & siteCode & """", "Refresh", , , context
        
    Query = "SELECT * FROM SMS_SCI_SysResUse " & _
            "WHERE RoleName = 'SMS PXE Service Point' " & _
            "AND SiteCode = '" & siteCode & "'"
    
    Set SCIComponentSet = connection.ExecQuery(Query, ,wbemFlagForwardOnly Or wbemFlagReturnImmediately, context)
                       
    ' Only one instance is returned from the query.
    For Each SCIComponent In SCIComponentSet

         ' Display SMS PXE service point server name.
         wscript.echo "SMS PXE Service Point Server: " & SCIComponent.NetworkOSPath                                    
    
        ' Loop through the array of embedded property instances.
        For Each vProperty In SCIComponent.Props
            
            ' Setting: ResponseDelay
            If vProperty.PropertyName = "ResponseDelay" Then
                wscript.echo " "
                wscript.echo vProperty.PropertyName
                wscript.echo "Current value " &  vProperty.Value               
                
                ' Modify the value.
                vProperty.Value = delay
                wscript.echo "New value " & delay
            End If
 
               
        Next   

             ' Update the component in your copy of the site control file. Get the path
             ' to the updated object, which could be used later to retrieve the instance.
             Set SCICompPath = SCIComponent.Put_(wbemChangeFlagUpdateOnly, context)
    Next
                          
    ' Commit the change to the actual site control file.
    Set InParams = connection.Get("SMS_SiteControlFile").Methods_("CommitSCF").InParameters.SpawnInstance_
    InParams.SiteCode = siteCode
    connection.ExecMethod "SMS_SiteControlFile", "CommitSCF", InParams, , context
      
End Sub

public void SetResponseDelay(
    WqlConnectionManager connection, 
    string server, 
    string siteCode, 
    int delay)
{
    try
    {
        // Get PXE properties.
        IResultObject ro = connection.GetInstance("SMS_SCI_SysResUse.FileType=2,ItemName='[\"Display=\\\\" + 
            server + "\\\"]MSWNET:[\"SMS_SITE=" + 
            siteCode + "\"]\\\\" + 
            server + "\\,SMS PXE Service Point',ItemType='System Resource Usage',SiteCode='" + 
            siteCode + "'");

        // Get the embedded properties.
        Dictionary<string, IResultObject> embeddedProperties = ro.EmbeddedProperties; // Get a copy

        // Update the response delay.
        embeddedProperties["ResponseDelay"]["Value"].IntegerValue = delay; // In seconds.

        ro.EmbeddedProperties = embeddedProperties;

        // Commit changes.
        ro.Put();
    }
    catch (SmsException e)
    {
        Console.WriteLine("Failed to set PXE response delay: " + e.Message);
        throw;
    }
}

The example method has the following parameters:

Parameter	Type	Description
connection	Managed: WqlConnectionManager VBScript: SWbemServices	A valid connection to the SMS Provider.
context (VBScript)	VBScript: SWbemContext	A valid context object. For more information, see How to Add a Configuration Manager Context Qualifier by Using WMI.
server	Managed: String VBScript: String	The Configuration Manager site server.
siteCode	Managed: String VBScript: String	The Configuration Manager site code.
Delay	Managed: Integer VBScript : Integer	The delay, in seconds.

Compiling the Code

The C# example has the following compilation requirements:

Namespaces

System

System.Collections.Generic

System.Text

Microsoft.ConfigurationManagement.ManagementProvider

Microsoft.ConfigurationManagement.ManagementProvider.WqlQueryEngine

Assembly

microsoft.configurationmanagement.managementprovider

adminui.wqlqueryengine

Robust Programming

For more information about error handling, see About Configuration Manager Errors.

Security

For more information about securing Configuration Manager applications, see About Securing Configuration Manager Applications.

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